Yeah you have no idea of time passing when put under. No matter how groggy you are when you normally wake up, you have like an intuitive feel about how much you've slept. Sometimes its wrong several hours and that feels weird.
But when put under the intuitive feel is just like as if had been minutes. Or two days. Your brain has no idea. It's a weird feeling, yeah.
I don't even know how many times I've been under. Many.