My friend with weird motor movements

When I was in my primary school, I had a best friend who has rather odd sudden involuntary movements of his body. At times, it would appear as if he was being startled, or like there was an invisible bee buzzing around his face, hands and legs, which will sting him at random times.

There was once when we were required to sing our national anthem, and was required to stand straight up. He was standing right beside me, and because of the involuntary movements, he could not keep 100% still. His legs would appear to be minimally rocking back and forth. Unfortunately, we had the discipline teacher standing right behind us. He thought my friend was playing a fool, and hence, punished him for making fun of the national anthem.

We went our seperate paths after primary school. Only when I entered medical school did I realize..he actually had Tourette's syndrome.