Is it normal to imagine killing everyone you love?

i always imagine that I'm looking onto a stage from the light and sound control box, and everyone i know is on individual small circular platforms on the stage. it is my job to "weed out" the group. and as two platforms are automatically moved to the front of the stage, i must press a button and kill one of the two. the people can see me, and they know what i am doing, and that i control their fate, but we can't speak to each other, i can not explain myself. -it starts off fairly easy, but then i must choose between my best friends, boy friends, and family. I'm always allowed to 'keep' one family member and 2 friends- one girl, one boy.

the story ends one of three ways. 1. everyone remains dead and there was nothing i could do to change it. 2. i discover a very obvious button, that if pressed, could have easily saved everyone, and they all died for no reason. or 3. it turns out when they were 'killed' they were really just pulled underneath the stage, and they all come out after the 'choosing game' knowing who i picked before them and what number they were killed etc...

why do i constantly think about/dream about this? is this a clue to some sort of anxiety or is it normal? please post a comment if you think of similar things, or have any suggestions for me.