Built-up tolerance? After drinking triple espressos like water in university I could drink coffee at 10 pm and still fall asleep an hour later. Of course, I'd w

Built-up tolerance? After drinking triple espressos like water in university I could drink coffee at 10 pm and still fall asleep an hour later. Of course, I'd wake up feeling more tired than before with a splitting headache, but that's what the triple espressos were for.