smart john once told me that a leading theory about yawning is that we yawn when our bodies aren't getting enough oxygen. you do this a lot when you're tired because your body is getting lazy and not drawing in enough oxygen.

smart john went on to say that yawning is contagious autonomically; a biological survival deal. if you see the guy sitting next to you yawning, your body vibes that there isn't enough oxygen in the room/cave/space and thinks it also needs to yawn so you can get a big ole mouthful of air as well.

i have no idea if this is true but i liked it when i heard it. it's become a rubik's cube of sorts sitting on the coffee table in my brain. a curiosity picked up a few times a year and spun aimlessly, knowing i have no prayer of making sense of the riddle but oddly compelled to study it for a few yawn-free moments every now and again.