I found it notoriously difficult to follow lectures at uni and always did something on the side, like surfing the net.
Yet I did finish my M.Sc. in Computern Science as the best of my year. I was able to study well. Which is one of the main reasons why this somehow never seemed to fit for me, I have two close friends who were diagnosed with #ADHS as kids and who really need their meds to be able to do well.

Then again, I'm also gifted (as a kid my parents took me to an IQ test, was >130).