I didn't have my first coffee until I was 23 and a fifth-year senior in college. A particular class, which met twice a week, gave out about seven hours-worth of homework each class. It met at 8:30am on the days we had it, and with senior project, some (though minimal) social life, doing my small part in planning our wedding, and such looming, I often was doing homework late into the night before the class. There were nights when I just didn't end up getting any sleep, and energy drinks weren't cutting it anymore.
I'd accumulated a lot of meal credits, so I started using them at the campus coffee shop. After a particularly long all-nighter, I ordered a septuple shot of espresso, and other times, when I ordered coffee, it always had a shot or two of espresso in it. No cream or sugar.
Since then, I've pretty much been a 3-5 cup of black coffee a day guy.