Inspired by this question. The “Superboy” in that question not only isn’t the “original”, his origin story even as the “new” Superboy has apparently changed multiple times.
There was a time when comic character bios were seemingly set in stone. Sure, we’d have the occasional “imaginary tale,” but in general the modern practice of constantly reinventing origin stories and renaming secret identities was unheard of. I’m interested to learn who first decided that this was a thing. What was the first time in comics that a superhero got a completely rewritten origin story?