And I was taught it by a PADI Course Director who had been himself taught it by a PADI Course Director, but it is nowhere taught officially by PADI.
That same PADI Course Director was the first person I DM'd for, and he came up with a bright idea of his own. When teaching students how to help each other gear up while standing beside the pool, which he scheduled right before the giant stride entry, he realized that if they put their fins on in the correct order (with the figure 4 technique holding onto the buddy's shoulder), they would end up facing the pool, ready for the giant stride. Before long, it became a required step in the process, and people not doing it were not doing the skill correctly. Since he was the director of instruction for the shop, before long all instructors were requiring students to put their fins on in that order. When I became an instructor, I realized it was stupid, because divers gearing up that way are not likely to be on the side of a pool preparing to do a giant stride, and they had to face each other for a buddy check anyway.
Decades ago agencies wanted to teach students that inhaling made them more buoyant and exhaling made them less buoyant. They wondered how best to do that, and the fin pivot was born. That was its only purpose, because it is not something you ever actually do on a dive. Well, instructors all over the world made it an art form, with elaborate rules (knees locked, fin tips on the floor at ALL times, never touch the floor, arms folded, etc.). What was supposed to be a simple little learning exercise became the hardest skill in the OW class. That is why PADI eliminated it years ago--it had become the Frankenstein's monster of scuba instruction.
I am sure many people can tell you stories of things that are taught in scuba classes that are not true and have never been a part of official agency instruction--the most famous being, of course, "if you put your mask on your forehead, a DM will assume you are panicking and will leap in to assist you."