A case of insomnia that one gets only on the night leading to Christmas Day. Christmasomnia is usually caused by the excitement of getting to open presents; a person gets so excited they can't fall alseep no matter how much they may want to and it makes the night seem that miuch longer.
Man, I had Christmasomnia so bad last night. I wasn't able to sleep 'til I had opened all my gifts and messed around with them for a while.
by TehDoc January 18, 2011