I've had this dream once before, but recently I've had it again.
It's night time, and I'm on the top of a hill standing behind a man. I hit him behind the head with a shovel, pushed him into a deep hole, and started to bury him alive. The process of shoveling dirt is monotonous and thoughtless. As I pat the last of the dirt on, the realization that I'm currently murdering someone hits me, and I begin to dig him back as quickly as I can before he suffocates to death. When I finally get to the bottom of the hole all I uncover are his mostly decayed remains, and I begin to panic. Suddenly a shadow looms over me and I finally see the guy's face, and he hits me across the face with a shovel.
The lesson I took from this is to not bury people alive.