Doctor with a sense of humour, by accident

I finally made my way to the clinic, and sought professional help for the ulcers and sore throat. This little clinic was nicely tucked away in a "hem" (small street), off the main road Hai Ba Trung St.

Dr Edgar was my physician. It started off fine. I told him about my ailments, and he did the usually stuffs like checking my temperature, breathing, heartbeat.... until he reached the knees.

"Cross your legs please", said Dr Edgar.
I cross my right knee over the left. He give it a couple of light tap with a rubber hammer.

"The other side please"
"Do you ride a motorcycle?"
The question came unexpectedly. I suppose he's trying to make conversation.

"Yeah, I do"

"Nouvo?"
At this point, my eyes nearly popped out of the sockets.

"You could tell my tapping on my KNEES??" I was bewildered. What sort of tricks was this? How could he tell?

He looked at me in the eyes. Unflinching, he replied,
"Your key's handing by the belt. It looked similar to mine. I ride a Nouvo."

You can imagine how stupid I felt then. Gosh, all those Panadols must have made me dumb. Of course he couldn't tell by tapping on my knees!

Oh well, we had a good laugh. For a moment there, he made me forgot about my sore throat and ulcers. So much for magicks.