People have said, the hardest part about creative work, is just starting. Once we do get started, most of us can do about 90 minutes of focused work before quality starts to drop. Sometimes you can spend a lot of time in front of a screen, canvas, whatever and not ever get into that focused work mode.
Thanks Adam，I will have a try,have a nice day.
I'm going to try the 90 minute thing - thanks, Adam!