For me there's a huge difference between the two. Without the meds, my concentration drifts. If I'm at home, I may be aware of an issue that needs attention, but lack the energy and focus to carry it out. I'll start watching a video, get distracted, and drift off there, then over there, and so forth.
Out in public it manifests as an occasional intense craving for sugar, though it's possible that's just me. At the peak it can be intense uncontrollable energy (the H part), as well as frequent "why did I come in here" or "I forgot to do this". It comes in getting distracted from a task and forgetting to ever come back to it.
With the meds, it's much different. I have a sharp focus. I can throw on a whole music cd and let the tracks all play out without feeling the need to jump around or to switch to a different album. Just me and the code that I need to do, or solving any other problem tasks.
In public I'm able to control myself better. I don't have to think of doing something before doing it as much, resulting in a better flow.
This isn't a matter of a diet either. I don't snack on fatty foods, and I don't have soda to drink at home. My current doctor has me take an EKG every year to make sure that it's not playing poorly with my heart.
There's a huge difference between "I get distracted from time to time" and having a constant difficulty getting tasks accomplished and lacking the motivation to complete small tasks from start to finish (getting interrupted and forgetting to go back at all).
I suspect this person has never encountered someone with actual adult ADHD. Consider also that in the past, many of these people would have just been called crazy and left at that.