What?

Two elderly couples were enjoying friendly conversation when one of the men asked the other,” Fred, how was the memory clinic you went to last month?"
"Outstanding," Fred replied. "They taught us all the latest psychological techniques: visualization, association, etc. It was great."
"That's great! And what was the name of the clinic?" Fred went blank.
He thought and thought, but couldn't remember. Then a smile broke across his face and he asked, "What do you call that flower with the long stem and thorns?"
"You mean a rose?"
"Yes, that's it!" He turned to his wife, "Rose, what was the name of that memory clinic?"