I first started coaching baseball when I was 18. The other teams adults would tell me to shut up! I coached baseball, basketball, and 17 years of soccer. I'm convinced kids sports are for learning, not winning. If the kids learn a sport well they will play to their best and winning is fun. But an hour later they don't remember the game. Only adults think winning is important and mess kids sports up.
When my youngest boy played soccer in high school I moved to coaching adults in running. They don't listen any better than kids. Running is the toughest sport to coach because runners are so independent.
I've been running since I was a kid, but I started training seriously when I was 44 when I went to an all comers indoor meet in Milwaukee to watch Jerry compete. Watching all those people racing was so much fun I decided I wanted to do that too.
My first race was a 10k in 1979. That's a different story.