a bigger fish - A bigger fish is when you’re so full of yourself you think y

A bigger fish is when you’re so full of yourself you think you’re the only one who matters, like a smug kid who thinks he’s the best at everything.

I’m not going to help you with your math homework, I’ve got a bigger fish to fry.

She skipped the meeting because she had a bigger fish to fry.

He had a bigger fish to fry than anyone else in the class.