Anyone else do this?

During those brief interludes when I watch TV shows and movies, I find it fun (and occasionally challenging) to grab the acoustic and solo along with the incidental music. Super frequent key changes seem to keep me on my improv toes.

I mean, it's basically just an excuse to hold a guitar during down time, but I like to think it has some value come jam days.

Yep. I've done it for years. I remember many years ago noticing that I'd occasionally jump in in the correct key. I thought it was a happy coincidence. Then it happened more and more often and I realized that I was starting ti "get it".