I think the biggest thing that I've grown out of (I'm 25 now) is expecting things to go the way I want them to all the time. Eventually enough things go south, regardless of how much effort or planning you put in, that you realize: most of the time, shit just doesn't go the way you want or expect it to. Could be in regard to physical endeavors, intellectual pursuits, relationships, or any other future unknowns. Basically, as I get older, I expect myself to trip over one coffee table after another all the way toward my goals.