Sometimes my weird knowledge of trivia can get in the way of working crosswords, as odd as that seems. Earlier tonight, I was working a Sunday puzzle from the LA Times. The clue was 'GUM competitor'. To me, GUM meant the gigantic department store of the Soviet era. I even tried to cheat by looking up GUM, the store, on Wikipedia. No hints there!
I finally 'worked round' the clue (fellow crossword addicts will know what I mean!) and filled in all the letters. The answer was ORALB, which still meant nothing to me. Finally, in desperation, I consulted a blog which gives the answers to every LA Times crossword for several years back.
I guess the problem was that I always buy generic toothbrushes! It had never hit me that GUM is a brand of toothbrush, and that ORALB when presented in its normal orthography is Oral-B. At least I finished the puzzle, even if I had absolutely no idea what that clue meant!