Recording yourself for YouTube has to help, but I’m really interested in what the author used to stay focused and productive for an entire nine hours. I can barely make it a half hour before getting distracted by something.
I started this at about 14:00 and finished at about 01:30, so about eleven to twelve hours wall clock time. And yes, if I hadn't been doing the recording I'd have given up and gone to bed. Also I, er, had to get up at 07:00 the next morning to go hiking.
even for 2~3h it's hard to keep my concentration.
I don't know how other people work but I just wanted to point out that at least for me often the reason for lack of focus seems to be not being 100% convinced that I want to do given thing. Because in reality there's usually plenty of reasons for doubt. So it takes some kind of "I don't care how rational that is, I just really want to do it".