Egg on my face.

"Ace, let's think of states that start with M."
"Mississippi!"
"Yep."
"Maine and Missouri!"
"Very good!"
"Michigan!"
"Awesome!"
"Ummmm..."
"There's another state that starts with M whose capital is Billings."
"Are you talking about Montana?"
"Yes! Good job!"
"Mom? The capital of Montana is Helena."
"...yep. Atta boy."