Why are they called Wisdom?

Does anyone know why those awful, painful, stubborn teeth that pop up in your mouth during your late teens-20's are called Wisdom teeth? Just curious. As far as I am concerned, they should be called Misery Teeth. They do nothing but cause people misery.
For about a month now I have been cutting a tooth. Isn't that nice. I get to be in the same boat as my friend's daughter who is a year old. Ha! I am too old for this. Anyway, this stinkin tooth is about 75% through the gums but that last little corner can't seem to push its way through--thus leaving me with a horribly painful mouth for about the past week. I've suffered in silence as much as possible because I don't want to seem like a crybaby after that whole kidney stone incident a couple of weeks ago. Matt mentioned that it seems like something is always hurting me these days. Well..it is. This tooth has been causing me bad headaches for at least a month but its only been the past week that my mouth has started hurting. It is so bad now that even my Tylox (which is strong pain medication) isn't helping AND for the past 2 days, I have been eating things like oatmeal and mashed potatoes so I can just slurp them instead of having to really open my mouth and chew. It hurts to swallow, chew, smile or even talk. The only time I feel halfway decent is when I am silent and still. But HELLO! I am a woman...and I am a go-go-go girl...so that is not working for me! Ha ha!
I did decide to make a dentist appointment today so hopefully we can get it all figured out and fixed. I go at 1 pm so wish me luck!