This is very true. I didn’t realize I had ADHD until after a year of college, but basically the first few days of taking stims are basically borderline hypo manic - you havw (seemingly) limitless enrgy, enthusiasm, confidence, drive. Work is intrinsically fun (although it’s actually extrinsic since it’s drug induced).

Then tolerance rears its head and it becomes exactly like you said. For me it takes till I get close to t_max (peak blood concentration) that my day really starts, which is from 1-3 hrs after dosing (closer to 3 for the drugs I take)