After telling me all about how he talked to "Grandma" last night, Aidan said something that made me realize he thought he'd been talking to Grandma F instead of Grandma S. In fairness, all of his grandmas are "Grandma" to him except for Nana. When I tried to explain which Grandma he'd been talking to, I said that Nana was a Grandma, too. He replied with, "No, Nana is Nana, not Grandma! Nana's an ogre like Shrek, not a Grandma!"
"Uh, ok..." was all I could say.