Why are those 'completely greenhouse-raised' so fragile? Thinking about how to deal with stress from the perspective of psychology and my own personal experience

There is a saying: 'You should buy hardship while you are young'.
Alternatively, there is also a deeply rooted macho ideology in the world that says, 'People should work harder and train themselves'.
Certainly, there is undoubtedly a need to intentionally take on stress as 'discipline,' such as the pain of long-distance running or the steady study that forms the foundation of what you want to do.
If we do not have the experience of receiving moderate stress and overcoming it, our minds and bodies lose their resistance to stress, and we become severely hurt by even the slightest burden.
Polarization of stress tolerance: People who enjoy the rain vs. people who get irritated

For example, try imagining what happens when it rains.
People without stress tolerance fall into a vicious cycle: 'It's raining -> It's unpleasant -> I'm irritated -> More stress'.
However, people with flexible resilience can, even when the wind blows or it rains, 'enjoy the sound of the rain' or 'savor the 'specialness' of having to stay at home'.
They are in a virtuous cycle where they feel less stress and do not invite further stress.
Thought experiment using extremes: 'Torture' and 'Greenhouse'
So, to become strong, should people endure any kind of hardship?
Here, I would like to conduct a 'thought experiment' using one extreme argument.
'To become strong, people should be subjected to torture-level stress from childhood'
'People should be raised in a sterile greenhouse with all the thorns removed so they are never hurt'
It is not hard to imagine that the latter, being 'completely greenhouse-raised,' creates a 'fragility' (vulnerability) that cannot withstand the trivial wind and rain of reality.
However, on the other hand, the former extreme is also undoubtedly flawed.
My experience: The distorted strength and price brought about by 'excessive load'

Here, I would like to share a little bit of my personal experience.
There was a time in my life when I lived in constant fear, never knowing when I might be hit depending on my father's mood. To put it mildly, this was excessive stress.
Ironically, this experience gave me a kind of 'abnormal endurance'.
For example, no matter how physically grueling a run might be, I can keep going, thinking, '**Compared to that unreasonable terror, this is nothing.**'
It is a fact that I acquired a twisted kind of strength, living out Nietzsche's idea that 'what does not kill me makes me stronger.' Therefore, there are parts of this harsh experience that I cannot say were entirely harmful.
However, at the same time, I developed schizophrenia, which will never be cured in my lifetime, andI have been left to suffer from the aftereffects of this stress forever.
In medicine and psychology, there is a term called '**allostatic load**'.
Humans can recover and become stronger from moderate stress, but if they are continuously exposed to chronic and excessive stress, the mind and body's systems themselves wear out, eventually leading to irreparable 'breakdowns'.
They say that 'a small amount of poison can be medicine (hormesis effect),' butpoison that exceeds a lethal dose is, after all, just a deadly toxin.
Conclusion: Determine the 'moderate thorns' for yourself

You should exercise for your health, but it would be counterproductive to break your body with excessive training and be left with a lifelong disability.
In the same way, there is a clear line that must not be crossed when it comes to 'hardship for the sake of building tolerance'.
We cannot live in a 'greenhouse that knows no thorns at all.' However,there is absolutely no need to 'voluntarily enter a torture chamber'.
What is needed is to find the 'middle ground' between those two extremes.
While sometimes facing unpleasant studies and learning the wisdom to get through rainy days, we must determine what is 'moderate load (medicine)' and what is 'excessive load (poison)' for ourselves.
Before we take the saying 'seek out hardship while you are young' too literally and completely destroy our mind and body systems.
I believe we need to move away from extreme arguments and calmly determine the 'number of thorns that is moderate for us'.
