Atishoo

There are few experiences as common as that minor ailment known as common cold, where you sit on a train with people staring at you like an extraterrestrial creature, abashed with water running down your nose. And at the same time, you're running out of tissue paper.

Common cold is going to happen to everyone of us. You may feel a little as if having a cold is the sine qua non of having a winter. But, you might ask, why the heck do we sneeze when we catch a cold? What purpose does a sneeze serve, apart from embarrassing us on the train? The best perspective to take, as pointed out by Richard Dawkins, would be from the virus's point of view. From the standpoint of the virus (or more precisely, the standpoint of the genes that create the virus), I was told, it has evolved to manipulate the human respiratory system to expel it into the air, which in turn makes it more likely to infect more people. This makes sense.

Think of an even better-adapted cold virus that infects its host's nervous system and compels the host to kiss other people on the mouth.

If you find that idea weird, well, think about the rabies virus.