it comes with time. you get thru things a few times, and you realize how little things matter in the long run.
old people... fat, out of shape, bald, stinkin... they dont give a shit, because they've seen the world they grew up wtih disappear, they've seen most of their loved ones die, adn they've seen the whole new generation of crap dominate culture, over and over.
Time. Give it time and you'll be a hard jaded MFer.