I'm 55 and I love eventing. I gave up on the idea of ever making it to prelim, and am happy to start babies, and school and compete lower levels till they are saleable. The funny thing is, it's probably harder riding the green ones over jumps, than a well schooled horse over the bigger jumps, but I am comfy and happy.
My plan is to take up endurance riding when I'm too old to jump.
I sure like a mounting block these days, soreness in my knees makes it a little harder to mount than it used to be.