You are conscious of most things your brain does. Background tasks like walking and chewing gum tend to be very rote and decision light. Try and write while listening to someone speak, fold a paper airplane while navigating a new city, or program while watching a film.
Writing, listening, watching a film and navigating a new place all require attention as they're novel activities. But I could easily make a shit paper aeroplane while navigating, and I've coded through pure muscle memory plenty of times. Almost any activity can be internalised.
> I've coded through pure muscle memory plenty of times