That operator's one I've used more on puzzles than in real life, where I've used it few enough times in 15ish years that I could count them on one hand. I think it only sticks in my mind because, for whatever reason, it was taught early and with some emphasis in a Perl book I read when I was starting out. If not for that I could well fail to come up with a reasonably "correct" solution to FizzBuzz.