In one of my first classes upon returning to university, one of my professors urged the class to "think ahead to the future. What do you see yourself doing at the age of 23?" I laughed at the time, as I didn't remember what I had done just a few years previous. It was a reminder however, that returning to undergraduate studies as a part time student would bring an increasing age difference. It hasn't stopped me from making friends with my classmates, although they have this nasty habit of graduating and moving off for grad school. I hear conversations about parties, and bars, or just going out to see a movie last minute, and I just shake my head. I have to remember if I need to pick up another pack of Pull-Ups on my way home. Life has a tendency to catch up, when you're not expecting it.
One of the coop students in the office once revealed that they are younger than the Simpsons TV show. While they didn't watch it as a child, they have not lived in a world without Bart Simpson. That's kind of a cultural touchstone for me, and its disconcerting to learn that it predates people I work with.