When I was in med school, I had the following conversation with another student, who was studying medicine as a second career:
Classmate: "I still remember during Operation Desert Storm, my college roommate put up a sign on our window to protest."
Me: "I don't remember Operation Desert Storm very well. I was just in grade school then."
Classmate: "No, you weren't!" [thinks a minute] "Oh my god, you were! Oh god! That makes me feel so old!!!"
Of course, he was only in his late twenties, but I guess it's kind of weird to be 30-ish and training with students who are 22 and fresh out of college (like me). Personally, I think if situations were reversed, I would have been bothered by all the young whipper-snappers.
The average age in my class was 24, which was probably the median age as well. It definitely seemed like there was a disconnect between the students in their late 20s and the under 25 crowd. It seemed like the older students had their own group of friends. Although frankly, I thought we were the more mature ones, in many ways. I may not have known as much about the world as they did, but at least I never made obscene gestures with a banana during histology lab.