What is something you thought you had discovered or invented, but it turned out to have already existed?

https://lemmy.world/post/155433

What is something you thought you had discovered or invented, but it turned out to have already existed? - Lemmy.world

egoism, then again i was a kid

also drones, i thought i was a genius for coming up with the idea of remotely controlled optionally weaponized vehicles with cameras

I had the idea for a printer/scanner/copier/fax. Copier = scanner + printer. Fax = scanner + modem.
As a PhD student, this is my day-to-day 🥲
This is stupid, but I thought I'd invented a shape of cup bottom that wouldn't accumulate water in the dishwasher, but that was still stable while standing upright. Found a patent for my exact design after working on it for months.
That sounds brilliant!