Series of Dreams

I tend to have violent dreams every so often. I remember one period I had one where I was hanging out with several friends or something and this stranger was annoying me to no end, and eventually I lashed out and killed him, did a sloppy job of hiding the evidence, and spent the rest of the dream in fear that the cops would find me but with little remorse for the act.

Is this a manifestation of selfish tendencies personified, or just um...stress impacting what goes into my head?