> Karpathy described it as a form of coding where you "fully give in to the vibes, embrace exponentials, and forget that the code even exists"

If that's not "turning your brain off", what is?

That's the definition I am aware of, yes. It's also in the term, that you let a vibe (a force coming from the outside) decide what your work lead to, as opposed as to deciding where it should arrive at and leading into that direction.

What is your definition? Is there any difference between AI assisted development and vibe coding to you?