Another way of reading the saying is that the weak men are weak mentally, they're cruel and inept. So maybe outwardly "strong"... but not really.

It's a nice reading, and I do think that the ability to take the wider view, to be prepared to suffer and fight for principles rather than immediate personal gain, to band together with others even at personal cost is an enormous strength.

I just don't think it's what people using this phrase mean.

>to be prepared to suffer and fight for principles rather than immediate personal gain, to band together with others even at personal cost is an enormous strength.

The more I think about it, the more I come to realization that all of this just fairy tales for children.

Of course! Fairy tales for children are how we communicate some of our best understandings of what it means to live a good life.

Many important things in life are fictions or rely on fictions - money, nations, property, family, art, justice, legitimacy, banks. All of them are fairytales. And like a fairy in Peter Pan, belief can make them real, powerful facts of our world while lack of belief can destroy them.

It works too - I know lots of real people who make the world a better place because of the fairy tales they choose to believe.