Piano players also tend to be the ones who know the "other" verses to carols. Most of the 4-part piano parts are pretty easy, so we have lots of time to look over the other words. Some of the carols have a lot of verses; We Three Kings and Good King Wenceslas have 7 each.
Of course, like most men, I can't hear the beginning of "We Three Kings Of Orient Are" without trying to finish it with "trying to smoke a rubber cigar.