Is it normal to feel calmer on stimulants than off them?

For someone with ADHD, yes. Stimulants increase dopamine and norepinephrine in areas that regulate focus and impulse control. When those systems are underactive, the brain can feel noisy and chaotic. By improving regulation, medication can reduce that internal restlessness. To others, stimulants sound activating. But for the ADHD brain, they often create clarity and calm. Feeling calmer is actually a sign the medication is working as intended.