Has there ever been a piece of media where the protagonist has a mentor and the mentor is actually the protagonist but older that time travelled back to stop their younger self from making the same mistakes they made in the “original” timeline?

Follow up: is the mentor also a huge asshole to their younger self?

Fate/Stay Night

sort of

Lego Movie 2? Kind of?

Captain Simian and the Space Monkeys

🦋 ᛈᚱᛜⰞ : oh right! I forgot about Lego Movie 2

misfits comes close even if it's not really a mentor thing

First two seasons of The Flash, kinda?

Tanarian : kinda

This thought came about because I sometimes think about if I had time travel if I’d try to influence my younger self to make some better decisions (assuming paradoxes weren’t a concern)

But also I kind of dislike myself and I absolutely loathe younger me and I’m not sure I’d have the restraint to not smack a teenage or twenty-something me if I had the opportunity

Maybe you needed a smack?