If you're a well balanced person, at peace with yourself and your past, that should be no problem
I... don't know anyone like that. I'm fairly confident no such thing exists.
I'd like to think I'm at least a bit that way now.
There's not really much in my life I don't like, I mean, there's always things I'd like, but everyone has that, and I'm not obsessive over it. I'm happy with the way things are, and I don't worry myself over the past, what's done is done, and gone. I'm better off now.
Of course, I wasn't always like that, it took a long time for me to get there. (And trust me, high school didn't do a bit of help in that regard.) But in the end, it's all worth it.
Really the only advice I can give you (because calling me a role model in high school is not something you'd do if you knew me) is to never give up. No matter how difficult things might get, they can always get better. I've gone through a lot in my life, and I can honestly say without shame that I've felt like giving up at times. But I didn't. And because of that, I'm a lot better off, and a lot of the things that made life bad are over with now.
I guess what I'm trying to say is that no matter what happens, you should still keep trying. Failure will happen. Disappointment will happen. Things will get you down and I won't sugarcoat it. It'll be hard work, but you have to trust in yourself. And never give up.