Because i actually have real ADHD.

I have it so strong, that after I was preparing myself, my work desc, my books everything, i was starring into the books i wanted to learn for 15-30 minutes unable to just start or do anything.

With ritalin, i might have this mental block to, but its overcome in a few seconds.

I went from a 'nearly/borderline failing grade' to the nearly the best grade in just one year.

This changed significantly were I am today.