Yes, the forgetting does happen. Now, I still count my children twice and am always certain I forgot one, even when they are all there.
We had a very large family at my church forget one of the daughters at a parish soccer game.
Another family called them on their cellphone and said, “Did you forget something?”
Dad said, “No.”
Caller said, “Mary?”
The caller could hear the entire family flipping out.
And this is a VERY good family.