Everybody does some of the time, but not everybody does all of the time. I can relate: there is nothing like being tired, going to bed, have a hard/frustrating problem roll around in your head, come up with a solution you were agonizing over, then be wide awake, get up, hit the computer, then crank out code until your body puts you back to sleep.

It's one of the most rewarding (and rare) experiences of a hacker-entrepreneur. Sometimes you don't get this unless you've been head-down, balls-out. When I'm meandering through a problem instead of pouring everything into it, I rarely get these sorts of "eureka" moments.