Insomnia

According the the good folks at Merriam-Webster Online:

Main Entry: in·som·nia
Pronunciation: in-'säm-nE-&
Function: noun
Etymology: Latin, from insomnis sleepless, from in- + somnus sleep
: prolonged and usually abnormal inability to obtain adequate sleep
- in·som·ni·ac /-nE-"ak/ adjective or noun

According to me ('cause we all know I'm way smarter than those Merriam and Webster dweebs):

When your body is exhausted and is desperately in need of sleep, but your nervous system says "FUCK YOU, body! I don't wanna sleep!" And your brain starts thinking of 8 trillion things at once and you can't stop it, no matter how hard you try, and you toss and turn and beat the shit out of your pillow trying to make it conform to your head, which is obviously impossible, because the abnormal increase in brain activity must have caused your cranium to swell to an alarming extent. So you toss the pillow aside and plunk your noggin down on the mattress, which is fine for about a minute, but then it gets wicked uncomfortable 'cause your neck is bent at a weird angle. So you swear and pick the pillow up off the floor, brush the dust bunnies off of it (because you are FAR too lazy to clean, and even if you wanted to, you have NO IDEA where the cleaning supplies are located because you just moved into your stepmother's house and don't know where she keeps anything), and resume the pillow-punching cycle once again. This continues for hours until you hear your father and sister get up, get ready for work, and leave the house. You then give up entirely on sleep and compose a rambling and vaguely incoherent blog post while eating peanut-butter-filled chocolates that your received for Christmas.

I submitted my definition to the Merriam-Webster people, but they haven't gotten back to me yet. Must be a busy time of year for the dictionary industry...