I have been wondering this as well. I also wonder if being a "night owl" is related, as I'm only really able to work when I'm tired. Maybe I require a less active mind to reach motivation?
I’ve found that to be true in my case too. Many theories have been proposed but my personal favourite is [1]: "I can't start work until I've exhausted every possible distraction.”
Someone should invent a straitjacket for the mind.
