As I think about it, I'd say that the changes I've gone through are really more internal, and not particularly visible during typical social interaction. I certainly get along fine with and have plenty to talk about with people just entering college (as was obvious talking to you two last year at 4th Street; unfortunately, we won't be making out again this year). My views and attitudes haven't really changed much; it's more about focus, motivation, and attention. I guess it could be phrased as who I am hasn't changed much, but how I am that person has. For instance, back when I was 20, if I ran across a clever mathematical question, I'd jump on it and start trying to prove stuff. Now, it's still interesting in the abstract, and I might take a glance at it, but I'm not really motivated to spend time doing that as opposed to other things that seem more important now. (There's a reason nearly all mathematical breakthroughs are done by people under 30. Maturity is overrated in many respects.)