Great shots. You look like you're in great shape. I was looking good until last June, when my shoulder could no longer handle lifting and chin ups.
Yer keerect, age is (mostly) a state of mind. I just got my shoulder operated on for reattaching my rotator cuff, 3 muscles and grinding down a 1/2" long, 1/8" high bone spur. I call it my 100,000 mile tune up. (I'm 66.)
So I had to lay off ski patrolling for the rest of the year. But I do have my second Grand Canyon backpacking trip coming up April 17th. OH YEAH!
"There are no comfortable backpacks. Some are just less uncomfortable than others."