I never think caffeine helps people to really stay awake
it's more like 心理作用
whenever I drink coffee when I feel tired, at that instant I might think the coffee is making me more awake
but after a couple minutes, the "effect" disappears
This reminds me of a soda call "Jolt" I drink when I was in university studying for an exam.... You drink a Jolt, you don't even need to blink! I think they banned it now, anyone else tried it?