“Being bad at stuff” is also so selective. The other kids are not expected to be two years ahead in math, but I am expected to be able to sit perfectly still for 4 hours and pay attention in an oxygen depleted room. Everybody has to have this nearly exact same skillset.
It’s not what society needs, not even what the industry needs in the workforce, but that is most convenient for the teachers.
It can take time to find the right dose.
I even started with 5 mg only, and it felt great. Crashed after just 3 - 4 hours, and within the first week figured that 12 mg is right for now.
The individual differences can be enormous.
This guide to understand dosage finding is pretty good, but doctor’s orders first: https://www.adxs.org/en/page/232/dosing-of-medication-for-adhd