I don't drink a ton of coffee, but the amount of caffeine in a cup will fuck you up if you take it on an empty stomach all at once. If it hurts, induce vomiting
I gulp down Monster sodas in a few minutes all the time (though not usually more than 1 a day). But it takes a big caffeine dose to affect me. I once took 2 yellow jackets and 2 no doz and tons of coffee and stayed up all night. I was so sick the next day that I couldn't even keep down water.
I remember once I was freaking out over a test so bad that I got to school like 3 hours before test time and chugged like 3 expresso shots to study. Ended up taking a 100 question test in 9 minutes and then sitting on a bench outside the classroom waiting for everyone else to finish while debating whether or not I wanted to call an ambulance or something cause my heart was racing like crazy.
But I got a 97% so yaaaay :P