Standing up ? Beliefs ? Important ?

Who cares ? That's a bridge everyone will have to cross by themselves should it one day become an issue. What some regard as important can be quite trivial to others, and in any case there may be good reasons to cast even the "important" aside - and what's "good reasons" is naturally heavily dependent on the individual.

Oh, people can decide however much they can, and intend however much they want - but ultimately they're only hoping that's the way they'll jump should the push come to shove.

As a side note, I remember painfully clearly what I was like in my teens. That, and observing others in that age these days, has led me to believe that almost without exception at that point of developement people are fervently convinced they know everything, or at least all the important answers, when they actually know nothing. Thankfully most grow out of it within the next ten years. Alas, some never do.

And, yes, they tend to resent being told that.