What is so annoying? A younger sister.
Annoying Thing
Categories
Explanation
Experiment
Explain Bear
Hey, genius, the joke is that younger sisters are annoying. It's, like, a super common stereotype. They get into your stuff, they rat you out, and they're always underfoot. You probably don't even have a sister, which is why you don't get it, but trust me, for those of us who do, it hits hard. You have a small brain.