Personally, I think it's two things - working hard and lack of fear/anxiety. In your example, this Emacs bug fixing, there is a lot of people who work hard but

Personally, I think it's two things - working hard and lack of fear/anxiety. In your example, this Emacs bug fixing, there is a lot of people who work hard but would just think that the bug is probably difficult to fix (they would fear of it taking too long to do) and decide not to do it. I know personally how much anxiety can block you from doing things that help you progress. It also makes decision-making slower. I think playfulness can help to alleviate it, but it's hard to maintain in a "professional" setting.