There's a lecturer who's usually so dry that he makes the students fall asleep. The lectures last for 2 x 45 minutes, and my friends and I usually fell asleep during the first 15 minutes or so. Once I decided to go there and try to stay awaken. I hadn't drank coffee, energy drinks or anything that would make me more brisk. I just went there, and while my friends fell asleep, I didn't even get tired, fall asleep or get the "lights out for a while" effect during the 2 x 45 minutes. My friends asked me if I was badly ill or something because I couldn't fall asleep on that lecture.