I noticed that I can't do more than 5 quality hours of work as well. And mostly, it's all about density. 2 hours of debugging a tricky issue, while having your

I noticed that I can't do more than 5 quality hours of work as well. And mostly, it's all about density. 2 hours of debugging a tricky issue, while having your tools fail you multiple times in the process, can drain me out for the remainder of the day. On the other hand, doing an interesting research/notes-taking or other non-infuriating work, and I might spend 6 hours without even feeling too tired. On average, 4-5 hours of _actual_ programming (thinking, writing, refactoring, testing, documenting) is all I can squeeze out for a day. Is this normal or am I not pushing myself enough? I'm not sure.