There is one factor I haven't seen addressed: mindset. If you have certainty in what you're doing, if you have belief, it's a lot easier to be productive than

There is one factor I haven't seen addressed: mindset. If you have certainty in what you're doing, if you have belief, it's a lot easier to be productive than if you're questioning everything ("Why am I doing this?", "Is there a better approach?"). That outlook on life has scuppered my productivity at times.