Guy who sits next to me in shul is a Lubov. He say "omain" during the parts of davening when I say "ken yehi rotzon." He's playfully mischievous and so am I, so we both are given to saying the words a little louder than we should, when the other is around.
Last week, he showed me an essay which argued that "omein" was the correct response. He was very excited, and very convinced by the brilliance of the argument.
I wrong-footed him this way:
"Here's what we should do," I said. "Let's get together three gorups of Jews. One will say "omein," the second will say "ken yehi rotzon," and the thrid will say nothing. They are our control group. At the end of a week, or a month, or a year, we'll check in on the groups and see who's doing better."
My friend went back to his book with a sour look on his face.
Oh, well.