Butter Knife

Just now as I was slicing a banana to put on my cereal, I noticed an interesting thing. I was using a butter knife and I turned it so I was cutting with what would be the cutting edge if it were a sharp knife. But a butter knife is just as blunt on both edges and I could have cut the banana just as easily with the back side of the knife. Must be an ingrained habit that knives are to be used only one way.