Bougainvillea

"Did you have a nice time yesterday?" I ask Mom. "Remember? Bill visited you for Mother's Day and we went to church and then to the beach."
"Yes," she says. "Bill was here."
"And I had that bougainvillea," she says, stunning me into silence.
~ ~ ~
How did she remember this word? There's so much she can't remember, especially short-term memory, and I've never mentioned this flower to her before. How did the word stick?
That afternoon I called Bill where he works at Ft. Lewis in Washington state.
"Bill, that flower they gave Mom at church yesterday, that bright pink flower--do you remember its name?"
"No," he said. "It was an interesting flower, but why?"
"First just think for a minute and tell me if you can remember the name."
"Okay--well, jacaranda?"
"No."
"I give up."
"Well, I was reminding Mom today what a nice day we had yesterday, with you visiting and all, and she said something about the flower, bougainvillea. I couldn't believe it."
He burst out laughing.
"So you better watch out--in this case, her memory was better than yours. Pretty scary."
"Yup, it is," he agreed.