I believe it calms me down a bit. I'm often quite incensed about things. Trying to think the opposite allows me to see things from another, or somebody else's viewpoint.

Also, I might get incensed by just the fact that I have to wait for traffic-lights to change! So having a mental task to perform at that time seems to help. It feels more like an opportunity then than obstacle.

I don't do it much these days but now that I read about Eno's oblique strategies maybe I'll give this some more attention :-)