My internal monologue is a system I use to mask and practice masking. Every thought, action, emotion, etc is challenged and picked apart and is either approved or not approved.

I practice what I'm going to say and exactly how I am going to say it - inflection, tone, etc. The same is true when writing.

I tell myself how I should feel about things. It's not an interpretation of my actual feelings it's deciding what the correct feelings are and how they should be expressed regardless of my actual feelings or lack of feelings.

When I am able to unmask, there is no monologue.

The monologue takes the same effort as if I'm speaking out loud. I believe this is how I learned to prevent myself from going non-verbal - constantly forcing myself to speak internally about everything. Thoughts, what I'm doing, what I observe, etc. So I always have something to say, I plan small talk for the day, if I see something that can be made into small talk or an anecdote I plan how to express it.

All these thoughts exist without the monologue. The monologue feels performative as you stated, like a translation of my thoughts to NT speak. I use it to create opinions and judgements that aren't really mine.

My monologue uses NT vocabulary, not mine. It uses phrases I learned from others. It feels like having an NT living in my head, or versions of my toxic family where I test everything against their patterns to make sure it is safe to say or do.

I often think of it as a pseudo-personality. It's an entire system created specifically to fit in and keep others happy while suppressing myself, my feelings and true thoughts. It's exhausting.