I've been thinking about birthdays and, more generally (but not much more generally!) age lately. I skipped first grade, so I've always been young for my age, and I usually took math classes that were a few years ahead of my grade. The upshot of this is that I was usually the youngest kid in the class by far.
So I think because of that, that kinda became my identity. It didn't matter that I wasn't the top student in the class (although I sometimes was) - for a while I was a novelty because I was so young, but even after that I could always tell myself that, even though kids did better than I did, I was younger than they were, so it didn't matter. In my mind, when I would consider my ranking in the class (I was pretty competitive academically for a while in middle/high school...), I was kinda in my own category, so I always won.
Another effect was that I started to identify as the young kid. So, even when I came to Rice, I wanted people to know that I was young, because that made me special. In the past, this had provided me with other people who would sorta hang out with me a bit just because I was young. (at Rice, I had the additional "specialness" of being a professor's son) And it did sort of continue at Rice, to a point (hanging out with djedi and blamantin wasn't just because I was young, but it certainly was a not-too-infrequent topic of conversation :-) ).
So now I'm out in the real world, and all of a sudden I'm not the youngest at work. And I felt kinda weird about that, and it took me a while to figure out why, and the preceding is what I came up with.
But now things are different (not that I'm making this change now, just that it happened a year or so ago). I don't feel the need to be "special" in some obvious way. I have good friends, a good job, djedi, and I don't feel like I need a "gimmick" to have people interested in me. This is healthy and a good thing.
And so, I guess I've become a lot more relaxed about age - I know occasionally people get sensitive about getting old and whatnot, and I do have those feelings occasionally as well, but I'm usually able to shake it off pretty well. Maybe it's like my rebelling against the hypersensitivity I used to feel to my age, but I just feel like it's something that happens and there's no point worrying about it. I used to be really bad about trying to change the past (when I was in high school and I would misplace something, I would always beat myself up as I was looking for it, wishing that I had put it in its right place), and now I just try to deal with things in the present as they come up.
(Disclaimer: nothing in here is meant to blame djedi or blamantin for my age issues - I definitely had them before coming to math camp/Rice. That is all.)