Counterpoint: I was professionally diagnosed as a child, my mum got me medicated, my dad got me off it a year later because it was "all about discipline".

Typical untreated ADHD style I excelled through early school until the later years of high school and struggled hard with procrastination, etc.

Got lucky with work for the first 8 years of my career in support work that is constantly changing, often high pressure which tends to capitalise on the ADHD brain but always struggled with anything long term, any project or case that takes more than a few days or weeks is a struggle.

Finally got re-diagnosed as an adult and it was LIFE CHANGING. Been on medication for about 10 years now. My psych retired and I was off medication for about a month and then briefly tried a different medication for another few weeks before going back to my original and it was miserable, I got almost nothing done for those 2 months.

I promise you, I just cannot think or disclipline my way out of it :)