I find it interesting how you take your experience and generalize it by saying "you" instead of "I". This is how I read your post:

> I don't know but to me this all sounds like the antithesis of what makes programming fun. I don't have productivity goals for hobby coding where I'd have to make the most of your half an hour -- that sounds too much like paid work to be fun. If I have a half an hour, I tinker for a half an hour and enjoy it. Then I continue when I have another half an hour again. (Or push into night because I can't make myself stop.)

Reading it like this makes it obvious to me that what you find fun is not necessarily what other people find fun. Which shouldn't come as a surprise. Describing your experience and preferences as something more is where the water starts getting muddy.