Eating crow
You have to eat something so gross it's like being forced to swallow a raccoon in a dumpster because you were wrong.
My brother had to eat crow when he said my new car was a piece of junk, and it turned out to be awesome.
My crush had to eat crow when he said I was ugly, and now I'm getting into college.
My teacher had to eat crow when she said I'd never pass the test, and I aced it.