Why am I so sleepy in class?

Why am I so sleepy in class? It's like a curse! I mean, seriously, who isn't fighting the urge to just faceplant onto their desk sometimes? Ugh, I've been there so many times. I remember one time in my history class, Mr. Henderson was droning on about the French Revolution – fascinating stuff, I know – but the room was so warm, and the lights were all dim… I swear, I actually started dreaming about Marie Antoinette offering me cake! (Maybe not historically accurate, but hey, dream logic, right?)

I think it's a combination of things, you know? Like, those classrooms… are they trying to lull us to sleep? The comfy chairs, the dim lighting... it's practically a recipe for a nap. And then, you're expected to concentrate for, like, an hour or more? My brain just shuts down. It's information overload! Sometimes I think it's just easier to give in. I've heard it's something to do with our circadian rhythms and stuff, like our bodies naturally dip in energy in the afternoon. I don't know, science and all that. But all I know is, sometimes sleep just seems so much more appealing than, say, the quadratic formula. Don't you think?