@clacke Ahh, black tea. Well, I believe that somewhere between 10 and 20 percent of the population is oppositely affected from the majority.
For them, caffeine is a sedative, methamphetamine is a sedative and appetite enhancer, diphenhydramine (Benadryl) keeps them awake and gives them nightmares.
I've met a number of people in this minority. It's a thing.