Places to go, people to be
My wife says I live in a fictional world. Aside from the fact that we all do - reality is a fiction, truth is a matter of the imagination, phenomenology, and all that - she's probably right.
When we went to see her family I was slightly more adrift from reality than usual (six hours sleep, three-hour drive, hormonal) like "I love you and I love your family but please know that I will mostly be thinking about pirate ladies kissing." She was very "I'd expect nothing less" about it.
In fairness to our dynamic she is very much the will-o'the-wisp, away with the fairies one, and I am the more practical. So on the occasion I need to tap out of reality she can take a period of holding down the fort.
When you're a bit tired that bleed is more obvious. Tiredness is scientifically similar to drunkenness, and like Hemingway said, write drunk and edit sober. That disinhibition is useful. Plus, I tend to have a lot of ideas when I'm driving. There's something about being in motion. Also that diffuse mindspace where I'm concentrating on one single thing but a lot of it is autopilot and my mind can wander.
"Places to go, people to be" is how I think about writing. Just going to open the door into another reality. Go somewhere else. Be someone else. Maybe not be but inhabit to some extent. I don't really feel like that about reading - I might inhabit the world but not the character. It's a funny sort of a hobby.