All. The. Time.
It is almost impossible for me to organise a sequence of actions, such as preparing a simple meal or even getting dressed, without narrating or "talking myself through it" to at least some degree. I also frequently catch myself saying random things, either out-of-the-blue thoughts, echolalia, or, most commonly, what I call "mirror echolalia" - where I see a word or phrase written somewhere and then can't stop saying it over and over. I am convinced that this talking is essential for learning and thought organisation. If people are around, I can keep it down for a while, but eventually sounds start to creep out.