Whenever my wife leaves town, I tend to get very melancholic (as in "Pensive reflection or contemplation," not anything having to do with black bile). I'm not sure why; I don't really get sad (well, I do in the sense that my wife isn't around and I miss her), but I defintely become more subdued, introspective, and I listen to music that matches my mood. I also find I tend to be in a writing mood (for fiction, not games) when this happens. I think it may have something to do with the fact that, once upon a time, I did most of my fiction writing when I was sad or depressed about something or other (most often girls), so it's kinda stuck in my wiring. I didn't do any writing over the weekend, though, but I did listen to some great melancholic music, including a new song by Daughter Darling called Colorblind (click to see the video), which was just perfect for my mood over the weekend.
Gotta go now to pick up my wife at the airport. :-)