I think when you say that it feels "stimulating," it's more of a side effect of being able to think clearly and behave like a normal person. As in, the symptoms of your ADHD are inherently related to your anxiety and stress levels (in that it is often the direct cause) and getting rid the ADHD symptoms removes that anxiety.

And as anyone who has ever had intense anxiety can tell you, it can literally feel like a weight lifted off of your shoulders.

Whereas, others are referring to it being "stimulating," in a different sense. As in the medication, directly, gives them more energy or euphoria (which is why there is a potential for abuse for neuro-typical people). For them, the "lift" and euphoria are directly related to the actions of the chemical, not a side effect of actually addressing a root issue of the anxiety.