specifically thinking about Superman from an in-universe perspective.

People know that Superman's real name is Karl El. He's an alien. He lives in an ice fortress in the north pole. For some reason he does most of his superhero stuff in Metropolis even though it's a bit of a commute from the north pole.

Scott Summers can canonically figure out angles and spacial geometry really well. It's how he's so good with his optic blasts. If I ever got a chance to write X-Men, I'd have him use this ability to hustle people at pool. Or maybe mini golf.

There's definitely a small but persistent group of people who insist that Bruce Wayne is leading a double life and fighting crime as the Green Arrow