It's because it's December. I get this every year, pretty much.
It's the association with every Christmas throughout my childhood when I got a bunch of new computer games, and got to experience the joy of playing them for the first time. Year after year, this association was enforced. I imagine most people on this forum have the same association.
When I wore a sweater all day for the first time in the season (only a couple weeks ago--I'm known to tolerate cold well) I felt a random urge to play Jedi Knight. The nostalgia's just been getting more intense since then. When my exams are finished, I'll finally have the chance to sate my urges.
It was always under, man. That was the point!
I'm just a little boy.