Go ahead and take legal cocaine though, hope your post helps you sleep at night
Do you know their entire medical history? How severe the ADHD is? Any other issues they are treating or not treating? If you can point to a study to back up what you are saying then by all means go for it. Otherwise all you have is anecdotal evidence and pretty weak evidence at that.
I get a new pharmacist every time I fill a script and I never share one iota of my diagnoses with them, they just fill the Rx and advise on contraindications and unusual doses they see.
Can you see into a person's brain with your own 'two eyes' as well? A neuroscientist can actually see our neural activity with fMRI and other tools to study brain science unlike your pharmacist buddies and yourself talking to random customers for 5 minutes in a grocery store.