The Best Kind of Motivation Is Not an External Reward

Psychologists say that the best kind of motivation is not when it has an external reward, but actually when the activity itself is enjoyable. What about drugs? Whenever i have to do something that will bore me, should i just get super high on drugs? And i ask this because i remember once a friend who does architecture and interior design said 80 % of people who come and do this certain kind of finish work, they're high. It's just too repetitive and ring and if you're not high, then you get miserable.