I don't know if it's age or not (I'm no spring chicken), but I do the same. As an example, I became quite skilled with the slingshot exactly this way. I set up a target catchbox between my office and my kitchen, and for a couple of years now, I take a couple of practice shots when I go between the two, or when I'm waiting for the microwave to finish, etc.

It was a year or so of doing this before I became a consistently good shot. Not quick, but if I had tried to set aside longer blocks of practice time, I wouldn't have done it at all.

Slow progress gets you to the finish line. No progress does not.