I quit racing a few years ago at racing age of 60. It was after going down in a training ride that was just one of those things. I flatted and slowed down just as a teammate was accelerating and looking backwards to see if there was any traffic from behind. It was a very hard crash.
At the time you would say that my teammate took the worst of it as he broke his collarbone and I just hit the deck hard. But my teammate was racing again in 6 weeks and I had horrible shoulder pain on every ride I took for 9 months.
That's when I hung it up. I rode for the next 2 years exclusively in the small chain ring: taking in the sights and smelling the flowers.
I miss racing. It is fun to be able to just get into the moment and not think about anything else. I used to compete in a couple of other sports (basketball and baseball when I was younger) and the only other one that compared was fencing.
I still dream about racing every once in a while. I had a dream about racing just last week.