Actually, reading to me isn't really thinking. It's more like being told things by another person. When I'm reading I pause reading every now and then, when I come across an interesting point, and think about it for a second. Those pauses are thinking, when I've stopped reading for a second. I've stopped reading to let myself think for a few minutes.
About how much time should be spent on thought? It depends on thought about what. I see thought kind of surrounding all the action I do. Pre-action, there's thought that leads up to deciding what to do. Post-action, there may or may not be reflection on the the thing I just did, or on the whole set of things I did in the past hour session or whatever. A Tae Kwon Do instructor I had sometimes encouraged us to do a "self-evaluation" after every class we had. To look back over what we had done and just "see" it, so we would notice where we might be able to improve, notice the things that we did well that we could be proud of, and notice which areas we weren't really confident with and needed more practice around. So I think that's a useful kind of post-action thought. Also, once I have some measure of skill at something, ie programming, I love to just sit and think about what I might be able to do with the skill. I imagine all the different things that might be possible, how I would go about doing them if I decided to do them, and what it would be like to do them. Also with martial arts, I would enjoy imagining some combination of moves. ie, could I do a spin off the wall then kick it before I landed?? Then trying those things I had thought up. That for me is just a pleasant kind of thinking. That's also the kind of thinking I was imagining with composing music. I don't compose music, but I imagine it goes something like that
