This is the conversation that happened last week.
DD: Mommy, Karen (not real name) came to my school today!
Me: Which Karen, sweetie? The one that used to go playgroup with you?
DD: No... Karen speaks Russian!
Me: (Realizing that DD could only know one Karen who speaks Russian, and that girl is a daughter of a friend. So I am becoming curious to know whether they are considering our school for next year.) DD, are you sure Karen never came to your playgroup?
DD: She is not in a playgroup. She came to my school.
Me: Ok, but when Karen was a baby, did she go to your playgroup?
DD: (looks at me as if I have two heads) Karen was never a baby!
FYI, we did eventually agree that Karen did go to DD's playgroup, but it took a while. I am not sure I was believed that Karen was ever a baby.