I play basketball on two rec league teams. My oldest teammate is 30, most are under 25. A while back, one of my teammates was asking me about my job and how long I'd been working in the high tech field. I told him I started working at IBM back in 1984. He got a funny looking smile on his face, so I changed my answer to "your entire life" to which he informed me he was born in 1987. That made me feel really old.
But, I got over it. So far, my 50s are the best decade of my life.