I think writer's brains are a little different from the regular population. Well, actually I think all artists brains differ, but maybe that is just my hope since my brain is different.
For example, I live in my character's world. The other day I was driving home from the dentist and a minor character in JUDGEMENT became a major character and a total bitch. She and the MC got into it because she wanted him and he didn't want her. She went as far as attacking him in the hallway and he shoved her into the wall while his LI watched. Talk about a mess. I made notes to write that scene.
There are other times too that can be rather embarrassing. Two weeks ago, in a fancy grocery store, I saw a man who was at least a foot taller than me and built like my MC, Stone. I stalked him through the grocery store picturing him as Stone and me as Larch and tried to figure out exactly where Larch's head would be when she hugged Stone. The man caught me staring and smiled at me. I could have melted into the floor, I was so embarrassed - probably blushed too. Who knows what he thought.
Some days when my husband comes home, I meet him at the door jumping up and down. "You won't believe what Stone did today!" He looks at me, gives me a kiss and says, "What did Stone do this time?" His tone is a little exasperated, a little amused and a little patient.
I was watching a movie in the theater when I went searching in my purse for my notebook and pen. My husband looked at me in confusion. I realized from a scene in the movie that I never described the elevator in my WIP and needed to quickly make notes about what it looked like so I could add it in when I returned home.
And my friends? They've stopped asking me how the writing is going because I talk about my characters as if they are real. And you know what - they are. Maybe that makes me crazy, but I really don't care because I am part of a group that is just like me. Are you crazy?