You might have a high tolerance and maybe fast metabolism. For me, caffeine and medicine has an effect that fades quickly and has weaker effect with each intake. When I first try something, the effect can be very strong, and I may have symptoms I'm not supposed to have. Like with non drowsy medicine and alcohol.
Everyone has different reactions to everything.
Obviously, caffeine in any form doesn't affect you. Maybe try bright lights, loud music, short naps. Wheat grass kept me up pretty good when I was in college. Made me too hyper to study, but it didn't seem to affect my friends much. But short naps and music helped a lot.