What's this free time you speak of? ;-)
I read on programming on my iPad in bed.
Once in a while I'll even program some Python on it, in bed, giving new meaning to the term "embedded programming".
I must confess, I rarely do anything professionally that I don't want to do anyway. In other words, I don't have to "make" myself do something - I do it 'cause I want to. I'm super curious.
That said, I need to learn Javascript for a side project. I don't find learning a JS very interesting in itself but combine it with something that do find interesting (3D graphics, Three.js) and it becomes fun. Sort of like spending time in France and learning French "accidentally".