"Productive" and "unproductive" are understandably pretty relative terms. I've accepted productivity is like efficiency -- I'm going to have some waste/inefficiencies and that's okay. That doesn't stop me from trying to make value judgments in choosing what I think are better activities for myself though.

Some people liken this to "hacking oneself"; I won't abuse the term "hack" quite so much, but I do think of it as a subproblem of "finding a job you love and you won't have to work a day in your life" -- finding a hobby you enjoy that enriches you as a person.