Once I memorized the alphabet backwards, just for the heck of it. I used the "ABC" song after a while to fix it in my memory. Years later, I was pulled over for a random license check / sobriety check. The policeman wrapped it up by asking me, yes, to recite the alphabet backwards --"starting with Q."
I hesitated. Mentally I began singing the "ZYX" song as fast as I could, got my place, and then quickly recited the alphabet aloud, perfectly, backwards from there.
Smart aleck cop. I know he had to be impressed but he refused to show it. He asked me "why I hesitated." I said something like "are you kidding?" or "wouldn't you hesitate?" He let me go and deeply satisfied, I drove away.
Years later I found children of a certain age go ballistic when I sing the "ZYX" song. "NO, NO, NO!" they scream in amazement, dismay, horror and a little glee.
I had the opportunity with my friends' kids this weekend. I even added a bit at the end. "Now we know our ZYXs. That's why we are nervous wreckses."