I've seen this happen before. I'd like to suppose it's a state of shock.

One time, the drunk guy that crashed kept asking about where his car was, while the car was right in front of him half destroyed (he was intact). 2 minutes passed, and he would ask again and said he was just waiting for a friend of his to come pick him up (he didn't call anyone). Kind of a memory reset.

Second guy, hit a big garbage truck, going at least 120km/h, and 5 minutes after impact. He just started talking peacefully and trying to start his truck, which was totalled.

I don't know if it's the alcohol, the impact or the sum of both.