When, I read this I see my 20 something self. I am 34 now, and while my life really hasn't changed all that much, my views have. The fascination all young men have with death. Not because they glorify it, but it is the last undiscovered frontier, and ever will be. I talked with a good friend (35) about this and he had the same feelings.
I think around 30 you come to terms with two things: You will always change and you probably will not grow up to be a rockstar. On the other hand you really start to appreciate your meaningless life.
“We live only to discover beauty. All else is a form of waiting.” - Kahlil Gibran
(this is totally out of Civ5 but it fits) Maybe because I am a scientist I view the world differently. There is so much, to learn and to discover. If you could see the inner workings and structure of a blade of grass in atomic detail with your own eyes you probably would break into tears of joy, for the excruciating beautiful chaos you just experienced. Not sure where I am going with this, but I want to soak it all in. All the life that is given to me.
For a few years I had a similar outlet. Pretty simple. I ran. I actually ran a marathon. I did not stick sadly. (the PhD crunch kills you) I am severely overweight again - but I know I can do it again, and spend the rest of my life solving the greatest mystery there is to me: women