I have never climbed one of those things but I'm fairly sure footed and disturbingly flexible for a man my size so I might do okay lol.

" I know that improvement doesn't happen as quick as you get older, but after just a few sessions I was surprised with just how quickly my strength improved."

I think some of the gains you make from earlier training are permeant so it is a lot easier to come back to something than it is to pick up something new. I was rather athletic in my teens and early twenties but I got pretty chunky for a couple of years before taking a back breakingly physical (but otherwise decent) job that has forced back into shape. When I started, I noticed that I hadn't really lost that much of my strength when I gained all my chub and my stamina came back pretty fast too. I don't know, It wasn't a cake walk but it didn't feel like starting over from scratch.