There aren't many books I wish I'd read when I was younger. That probably stems from the fact that I was a precocious kid. I started reading books above my recommended age pretty early. This meant that there were a few books I read arguably way before I should have. Subsequent readings at a later, more mature age have proven that.
However, one book I did feel that way about wasn't a fount of wisdom or a profound take on life as I know it. It was a mad scientist's light-hearted account of his mad scientist ways. Reading Richard Feynman's "Surely you're joking, Mr. Feynman" proved to me at age 28 that being a bit of an ass at times wasn't a bad thing per se.
It's not like I haven't been a wise-ass all along. I've tried to keep out of trouble mostly, but I have a stubborn streak that refuses to let me take things for granted without always questioning "Does it have to be this way?" or "What if I did that? What would happen then?"
Unfortunately (though I do try to reassure myself otherwise), that's not been always the case. There's a certain amount of kowtowing to the rules you end up doing to stay within the system. If you're as smart as RPF himself, and if you're in a society (MIT, Princeton, the Manhattan Project) which allows and embraces a certain sort of iconoclasm, it works for you. If you're not courageous enough, or a tad lazier, you start conforming and before you know it, you're 'The Man' you've been mentally railing against all your life.
Reading "Surely you're joking.." was a refreshing reminder that the curious child within each one of us can play even when we grow up and become adults. That a Nobel Prize winning physicist can paint (enough to get paid for your paintings) or play percussion in a samba band in Brazil. That the Renaissance Man isn't a Renaissance-era anachronism.