Well, while I do wish I started riding in my 20s or 30s, I don't wish to be that age.
I ride with a group of people who are mostly older than me a few times a year. One ride was lead by an 83 year old . My goal is to be like them. They might not be the fastest, but, they are out there doing things that 98% of all Americans don't do, like 40 mile rides, 8 mile hikes, and x country skiing.
And, I know I am in better shape now than when I was overweight in my twenties or anorexic skinny in my thirties.
There's nothing wrong with being a 50 something with an Amex in her pocket.