An ailment which causes people to accidentally write the wrong year on papers, applications, forms, etc. It is a very common disease that occurs directly after the new year, and can last for several months.
This disease is rarely a problem, since writing the year on most things is pointless anyways. However, serious side effects can occur when tax returns, college applications, etc. are affected.
Teacher: "You've written 2011 on every assignment you've handed in this month. You do know it's 2012, right?"
Student: "Yeah, I just have New Year Alzheimer's."