Note that ADHD can manifest physically, mentally, or a combination of the two. I've been recently diagnosed with ADHD in my late 30s after finally seeing a psychiatrist, and at most my physical manifestation of it is minor fidgeting.

Where it really burns me is not being able to dedicate brainpower for more than a few minutes at a time, unless I'm in one of my "focus" modes. Similarly, my brain constantly has multiple tasks/"conversations" going on and I'm always thinking of something else. Additionally, I'm always chasing something novel to satisfy some dopamine hit.

I've honestly worked around a lot of the issues I deal with prior to being diagnosed, knowing when I'm not in a "focus" mode and trying to (gently) steer back to being productive. I joke about my "gaming ADHD" where I don't sit with a game for more than a half hour or so before moving on to something else. Internal dialogues are just something I work with.

Not saying you're right or wrong, but it's difficult to compare someone else's problems with your own (potential) issues.

e: Also note that there are non-stimulants on the market. I'm currently trialing one while I wait for a cardiologist to review some records for possible stimulant conflicts.