Can You Put Your Finger on the Difference Between a Good Puzzle and a Bad Puzzle?

Can you put your finger on the qualities that account for the difference between a good puzzle and an annoying one? One of the keys is it requires innovative thinking. The phrase think outside f the box is a bit of a cliche. But that is really it, thinking in an innovative, surprising way. I talk in the book how something like seven times three equalsa seven times blank equals 21, and the answer is three. That's not a good puzzle. A but something like a a move. Oh, shoot, i fig i have it. Oh, good. Ye. 30 minus 33 equals three. You want to tell us the answer?