This sounds very much like the advice that Polya gave in his famous book "How To Solve It" -- it's an old book, but still in print. I wish I'd known about that book when I was in college. (I first heard about it many years later when someone told me that at the time it was given to all new hires at Microsoft. Don't know if it still is.)
If so, it seems that Polya wasn't always as diligently persistent as he advised others to be. There's a famous story about G H Hardy seeing a bear in a zoo: it sniffed at the lock on its cage, hit the lock once with its paw, and then turned away to do something else. "He is like Polya: he has excellent ideas, but he does not carry them out."
