The most common age group of people that suffer from Christmas Hangover is around ages 8-13, however, there have been other reported cases.
Symptoms include: forgetting what presents you even got, sickened feeling, tiredness, depression, ect.
Also when you've spent all your money on Christmas presents / food...etc... and can't afford to do anything, so you just lay about the house doing nothing
After buying my niece and nephew x-box games and my wife a diamond bracelet and all that food for the big day, I'm suffering from a christmas hangover!
Dude 1:Hey man what happend?
Dude 2:It was..............(he passes out)
Dude 1:Oh I get it, Christmas hangover (looks around then starts tea bagging him)