Can you operate at 100% on a single idea for 100% of the time? I can't. I usually pick up a book or drive to unwind and then come back to a problem. If I could

Can you operate at 100% on a single idea for 100% of the time? I can't. I usually pick up a book or drive to unwind and then come back to a problem. If I could get paid to do that- why wouldn't I try it?