Brazil, South Korea, China and England were all represented, though my pathetic effort of nine was never going to trouble any of them.
Surprisingly, Mr Woo did not laugh.
Instead he just advised me to practice, the same advice he gives to the huge number of young Koreans keen to emulate his skills.
"The only way to improve is to practice," Mr Woo added.
"I practice for many hours and work hard to develop my skills.
"As with anything, you only improve if you will practice and the hard work will pay off."
It has certainly paid off for Mr Woo, who is big box office hit in South Korea.
He is also a well-respected soccer coach but intends to continue to develop his career as a ball juggler.
It's a lucrative career - for as long as he can keep it up.