Very good summary of long term situation, I hope OP and similar folks would realize the drawbacks. Indeed, concept of 'free lunch' simply doesn't exist in reality, especially when it comes to drugs. Our bodies and minds constantly adapt and what caused a certain reaction before will gradually cause less of it the more its used. Some folks fare better, some worse, some have very low threshold for addictions.
A very US-centric view I think, i never knew a single person in my University who took these 'enhancing' drugs, we just got wasted from alcohol and smoked weed. And I went through rather stressful University where 2/3 of people who started were thrown out of school in first 2 years in one or the other filtering hardcore courses with slightly psychotic professors (still not getting why by far the hardest course from 5 years for studying freakin' Software engineering had to be 'Theoretical electrotechnics' with some hardcore math way beyond our actual math courses, of course never used any of that, not even on rest of studies).
Anyway, any substance you abuse will eventually kick back quite hard, if it didn't yet give it some time (or take a bit harder look in the mirror next time). Same for bad habits.
A very US-centric view I think, i never knew a single person in my University who took these 'enhancing' drugs, we just got wasted from alcohol and smoked weed. And I went through rather stressful University where 2/3 of people who started were thrown out of school in first 2 years in one or the other filtering hardcore courses with slightly psychotic professors (still not getting why by far the hardest course from 5 years for studying freakin' Software engineering had to be 'Theoretical electrotechnics' with some hardcore math way beyond our actual math courses, of course never used any of that, not even on rest of studies).
Anyway, any substance you abuse will eventually kick back quite hard, if it didn't yet give it some time (or take a bit harder look in the mirror next time). Same for bad habits.