For instance, what do the words speak, see-through, and categorical have in common?
While you’re thinking that over, I’ll tell you about the latest time it happened. I was sitting in a pancake house trying to master the New York Times crossword puzzle, and I couldn’t solve the upper right corner. The vertical clue that flummoxed me was “Unqualified,” and the answer was a five-letter word that seemed to begin with an s and end with an r. It also looked as if there should be an e or two in the middle. But hardly any words fit the letters, and none at all that remotely meant “unqualified.” Every few minutes I’d retreat to the corner’s horizontal words. Maybe I’d made a mistake with one of them. But if I had I couldn’t find it.
So I got up and paid and took a walk. And a few minutes later it hit me! The answer was a word I’d already thought of and rejected because its meaning wasn't remotely "unqualified." But yes it was—if you backed off and then came at the clue and the answer just so. Suddenly my mind was racing with wordplay.
So what do speak, see-through, and categorical have in common? Nothing at all, except that they happen to be synonyms of words that are synonyms of each other—as I stood there on the sidewalk and realized to my utter, sheer, and unqualified delight.