When I was 10, my mom signed me up for tennis lessons. I don't remember expressing an interest before then, but I do know I liked it once I started. My first year of junior high, I was on the tennis team, however briefly. I didn't play much after that.
Since the weather has cooled down from the triple digits we were having just a month ago, Oldest, his girlfriend and I have been playing tennis at the high school courts on the weekends. We played today, and I'm already sore. Working muscles that normally don't get worked. Fun stuff.