"What doesn't kill you makes you stronger" — why that isn't true of trauma

“What doesn’t kill you makes you stronger.” Nietzsche’s line has become a pop refrain, a motivational poster and a consolation that people with difficult experiences hear again and again — from those close to them who mean well, and from a culture that worships toughness. But from the therapy room and from trauma research I can say it plainly: it isn’t true.

Difficult experiences do not strengthen us in themselves. They weaken us — they burden the nervous system, unsettle the sense of safety and can leave marks we carry for years. What can strengthen us is not the blow. It is what we do with it: processing, grieving, support, integration.

The difference between those two sentences looks small, but it is decisive. The first version pushes people into silence and stoicism — if it didn’t strengthen me, I must be weak. The second opens a way towards recovery — the experience wounded me, and what I need now is not toughness but room to heal. This post is a thorough walk through that difference: what science says about trauma, what happens in the body and what the path that genuinely strengthens actually looks like.

Where the myth comes from

Friedrich Nietzsche wrote “Was mich nicht umbringt, macht mich stärker” in 1888 — a thinker who wrestled with severe pain all his life and whose thought was anything but a simple recipe for living. But the aphorism took on a life of its own and became part of a culture that psychologists sometimes call a culture of toughing it out: the belief that suffering is a test of character, that “strong” people endure without help and that asking for support is a defeat.

That culture has consequences. People with difficult experiences often suffer not only because of the experience itself, but because of what they conclude about themselves: “Other people managed to move on, and I’m still falling apart — so there must be something wrong with me.” In therapy this is one of the most common and most painful sentences. And it is built on a false premise: that blows make us stronger. Let’s look at what actually happens.

The hardening myth: what stress really does to the body

The idea that blows “toughen us up” feels logical because we confuse it with something that is genuinely true: a moderate, manageable challenge followed by rest really does strengthen us — that is how muscle training works and how psychological resilience is built too. The key words are manageable and rest.

Trauma is precisely the opposite. The stress system is designed for short bursts: danger, response, settling, recovery. But when the load is too great, too long, or arrives at a time when we are helpless — and trauma is by definition an experience that overwhelms our capacity to cope — the system does not return to rest. The neuroscientist Bruce McEwen coined the term allostatic load for the cost of that constant adaptation: a body that has to maintain readiness without pause is not being strengthened, it is being worn down. Elevated cortisol, which over time erodes the immune system, memory and the heart, is not training. It is wear and tear.

The strongest evidence comes from the ACE study (Adverse Childhood Experiences), carried out in the 1990s by Vincent Felitti and Robert Anda with more than 17,000 adults. Participants reported difficult experiences in childhood — abuse, neglect, violence in the family, a parent’s addiction or mental illness, divorce. The result was devastatingly clear and dose-dependent: the more such experiences there were, the higher the adult risk of depression, anxiety, addiction and suicidality — and also of cardiovascular disease, diabetes, autoimmune conditions and earlier death. With four or more categories of experience, the risk of depression was more than four times higher, and of a suicide attempt twelve times.

If it were true that blows make us stronger, these people would be the strongest among us. They are not — they carry the heaviest burden. That is not a judgement of them; it is an indictment of the myth.

What trauma actually is (and what it isn’t)

At the word trauma most people think of catastrophes: war, an accident, an assault. These are so-called shock traumas — a single event that overwhelms the system. But trauma is a broader concept. Therapists often describe it with a formula: too much, too fast, too alone. The event doesn’t have to have been objectively “bad enough” — what matters is whether it exceeded the capacity of the person living through it, and whether anyone was there with them.

So traumatic experiences also include what happened slowly and quietly: growing up with emotionally unavailable or unpredictable parents, prolonged humiliation, intimidation, emotional, physical or sexual abuse, and also experiences that people around us like to minimise — workplace bullying, a painful divorce, a loss that was not allowed to be grieved. Developmental or relational trauma leaves not a single memory but a pattern: beliefs about ourselves, other people and the world, woven into the nervous system before we had words for them.

It also matters what trauma is not: not every unpleasant experience and not every kind of stress. The decisive difference lies not in the event but in what happened inside us — whether the system could process the experience and return to balance, or whether it stayed stuck there like an alarm that was never switched off.

What trauma does to the nervous system

Each of us has a range of arousal within which we can feel, think and stay present — the psychiatrist Daniel Siegel called it the window of tolerance. Inside that window we can experience even strong emotions without being swept away: anger that doesn’t explode; sadness that doesn’t swallow us; fear that doesn’t paralyse.

A traumatic experience narrows that window. A nervous system that once lived through too much becomes over-sensitive to anything that might resemble it — and starts switching too quickly into one of two extreme states:

This explains why people after trauma often say: “I don’t recognise myself any more.” Someone who used to be calm now flares up over trifles. Someone who used to be lively is numb and absent. This is not weakness of character — it is a nervous system that changed its settings in order to survive. What was a solution back then is an obstacle today.

A narrowed window of tolerance also tends to show up in symptoms we wouldn’t connect with the past at first glance: chronic tension, digestive problems, exhaustion, difficulties with closeness — and very often sleep disturbance. A system that stands guard will not allow the surrender that sleep requires; I described that mechanism in detail in my post on insomnia and the nervous system.

The body keeps the score: where trauma is written

The psychiatrist Bessel van der Kolk, one of the most influential trauma researchers, summed up his life’s work in the title of his book: The Body Keeps the Score. Traumatic memory is not stored like ordinary memory — an ordered story with a time and a place — but in fragments: as bodily sensations, images, smells, impulses. That is why the past is not “remembered” but relived: it is triggered by a smell, a tone of voice, a touch, a season, and the body reacts as if the danger were happening now.

Brain imaging research confirms this: when people with post-traumatic stress disorder relive trauma, the amygdala (the alarm) is over-activated, while activity drops in parts of the prefrontal cortex and — most tellingly — in Broca’s area, the centre for speech. Trauma literally takes away words. That is why simply “talking about it” is often not enough, and why contemporary trauma work also involves the body: learning to regulate arousal, breathing and movement-based approaches, gradually widening the window of tolerance. It was precisely these findings that led me to further training in body-oriented psychotherapy, which I bring into my work — more on the page my approach.

So why do some people grow after trauma?

Perhaps you know someone who, after a hard experience, genuinely lives more deeply: they know more clearly what matters to them, their relationships are more precious, they get lost less often in small things. The psychologists Richard Tedeschi and Lawrence Calhoun named this phenomenon post-traumatic growth and have been researching it since the 1990s: people report deeper relationships, new priorities, a greater sense of personal strength, spiritual deepening and a greater appreciation of life.

But take care — the research is very clear here on three points that the myth overlooks:

• Growth doesn’t come from the event, it comes from the processing. Tedeschi and Calhoun stress that growth is driven by what they call deliberate rumination — slow, supported meaning-making of the experience — not by the experience itself. Without processing, only the wound remains.
• Growth and pain coexist. People who report growth often report symptoms of distress at the same time. Growth is not the opposite of suffering, but something that can slowly grow alongside it.
• Growth cannot be demanded. Expecting someone to “take something good” out of trauma can become a new form of pressure. Growth is a possible side effect of good recovery — not its obligation.

The same event can break one person and, years later, open a new chapter for another. The difference lies not in “toughness” but in the circumstances of recovery: how much safety, support, time and room for grieving they had. That is why the line “what doesn’t kill you makes you stronger” is unjust: it tells the person the experience weakened that they failed. In truth they didn’t fail — they were simply alone.

Recovery isn’t forgetting — it’s integration

In therapy we don’t “erase” trauma and we don’t forget it. The aim is that the experience turns from something that is still happening to you today — flashbacks, a body on alert, avoidance, freezing — into something that happened to you: a chapter of your story, not the whole of it. We call this integration.

The psychiatrist Judith Herman, author of the foundational work Trauma and Recovery, describes recovery in three interwoven phases that map well onto how this path looks in practice too:

• Safety and stabilisation. Before we touch the story at all, the nervous system has to experience again that safety is possible — in the therapeutic relationship, in the body, in everyday life. Without that, any digging into the past risks becoming a fresh flooding.
• Remembrance and mourning. At your own pace, with support, the experience is given the words and the tears it wasn’t allowed to have at the time. Grieving is essential here — for what happened, and for what should have happened and didn’t.
• Reconnection. The energy the past had bound up returns to the present: to relationships, work, the body, plans. The person is no longer primarily a survivor — they are once again the author of their own life.

These phases are not steps you climb in one direction; they are layers the process moves between. And the time they take is different for everyone — recovery isn’t a race.

What about resilience? How it’s really built

If blows don’t strengthen us — where does resilience come from? Here too science has a fine answer. Ann Masten, one of the leading researchers of psychological resilience in children, described it after decades of research with the phrase ordinary magic: resilience is not a rare, supernatural quality of the chosen few, but the result of entirely ordinary protective factors — at least one stable, warm relationship; a sense that you can influence your own life; a community that holds you; opportunities for manageable challenges with support.

In other words: resilience is not built through suffering, but through the experience that you are not alone in what’s hard and that challenges come in doses you can handle. A child who is picked up after a fall, comforted and encouraged to try again is building resilience. A child who falls alone is building survival strategies. Both can look like “toughness” — but only the first is health.

The same holds for adults: it is never too late for the nervous system to receive new experiences of safety. That is precisely the core of therapy — not persuasion, but a new experience of a relationship in which it is possible to be vulnerable and remain accepted.

What you can do if you carry a difficult experience

• Stop measuring your worth by “toughness”. The fact that an experience marked you is a sign that you are human — not that you are weak. Your symptoms were once solutions.
• Find a safe relationship. Trauma happens in helplessness and often in solitude; it heals in safety and connection. That can be a therapist, but also a group or a person who knows how to listen without advice and without hurrying you.
• Include the body. Movement, breathing with a lengthened out-breath, contact with the ground, nature — anything that tells the nervous system regularly and concretely: it is safe now.
• Respect your own pace. You don’t have to “face it” overnight and you don’t have to tell everything at once. The window of tolerance widens gradually — through repeated experiences of safety, not through heroic leaps.
• Give the process time — and company. Integration is not an event but a path. You don’t have to set out on it alone; that is exactly its most important difference from what wounded you.

I’ve written about why the strengthening myth doesn’t hold on Instagram too:

What doesn’t kill you makes you stronger … no, to ni res.

If you recognise your own story in this post — emotional, physical or sexual abuse, a loss, an experience the body hasn’t stopped remembering — know this: what you feel has a name, it has an explanation and it has a way forward. And you don’t have to look for that way on your own.