What's so stupid it's actually genius?

Honestly, those plastic clips that hold bags of bread shut are the ultimate example. It looks like the most flimsy, useless piece of junk when you first pull it off, and you're always terrified of losing it under the fridge. But then you try to find something better to keep the bread fresh and realize nothing else works half as well. It’s just a tiny piece of molded plastic, but it does its one job perfectly without any over-engineering.

Another one that gets me is the whole concept of "pet rocks" from back in the day. It sounds like the dumbest thing anyone could ever come up with, but someone actually made a fortune selling literal rocks. You look at it and think it's just a joke, but the fact that it was such a massive hit proves that sometimes you don't need a complex solution to make something work. Sometimes the most ridiculous ideas are the ones that stick.