I am not a regular consumer of energy drinks. Occasionally, I will buy and drink a can of a specific store brand energy drink, especially when the day is really hot. I enjoy the flavour.

What I’ve been taking note is that, usually, two days after drinking it, I will feel extremely psychically tired. I can sleep normally, even better, to a degree, have more dreams and even feel more mentally active during that period but after those 48 hours, I get extremely tired, to the point I can fall asleep if I stay still for to long. I can maintain myself awake if I remain active.

The drink itself has no unusual ingredients - taurine, guarana, caffeine, ginseng - but for some reason I am still unable to understand, it is the only one that affects me like this.

Note 1: I do not drink coffee. Caffeine from real coffee somehow alters my blood pressure radically. These energy drinks do not.

Note 2: I once drank one specific energy drink - a Battery - that kept me awake and functioning for nearly 60 hours. I was physically unable to sleep. When whatever kept me going ran out I slept for 30 hours straight.

Has anyone ever went through something like this?