Interesting topic (and comments).
1. I do inner monologue. And I have to say, sometimes I get scared from what I "hear". I don't mean sometjing like "I hear voices telling me to kill everyone", but nasty, brutally cynical, sometimes outright violent thoughts. They feel alien to me, because on general level I consider myself "the good guy", but one the other hand they don't feel like someone else whispering me evil things.
2. Sometimes I feel like my mind has layers, where this monologue is the the most upper one with some lower, less verbalized layer which is only later formed into words. Doesn't happen often, but it feels like the lower layer is actually more capable because it's not constrained by language/words.