I got home after a graveyard shift one time many years ago and had a minor existential crisis because I truly didn't remember the drive home. I read a couple of years ago that this phenomenon has a name: Highway Hypnosis. In theory, I shouldn't have been fatigued that day, but that's also a plausible explanation.
It took me a while to stop driving to an ex's place. I'd find myself halfway there. I was driving safely, but my directions were by habit not intention.