I stopped taking caffeine pills regularly when I stopped needing to be alert or freed from the effects of sleep deprivation — pretty much when I graduated college. The most interesting thing I have noticed about caffeine is how it makes me want to do things. My natural state is kind of lethargic, to be honest. Even when I’ve had plenty of sleep, I can just sit around and feel like doing nothing. I look at my to-do list and feel apprehensive. Thinking about doing any item is an unpleasant experience — my mind wanders and I do nothing at all.

When I take caffeine, I feel the opposite way. When I take caffeine, I have an intrinsic urge to do things. I look at my to-do list and suddenly the next few hours are a flurry of productivity. Aside from early morning exercise, I have found no close substitutes for the productivity enhancement I experience when I take caffeine.