A total lack of motivation

It's nearly amazing what happens almost every year in january. After the christmas break and right before all the exams. It's the like there is no sense in doing anything at all. Days pass by without I even started working or learning or something. I get up early trying to start soon and suddenly it's 10 in the evening and I haven't done a thing. Now that the exams are right in front of me I at least should learn a little bit. But my motivation is really at rock bottom. Hopefully this gets better in the next few days, otherwise I have a real problem passing all the exams.