Barry, another fan of yours here! I look forward to your well-written and insightful additions to this forum.
As for riding into the 70's, I fully expect to do so! Longevity and good health run on both sides of my family, so I at least have that going for me. There are also quite a few active and "older" horsewomen and men in my area who serve as inpiration. Presently my only limitations are in my mind, and maybe guilt for not taking care of my house and yard as well as I used to since I spend just about all of my free time at the barn. Priorities ...