Nevertheless, cultural differences were still common. Leung recalls that while his Chinese apprentices would never question their masters according to Chinese tradition, many of their US counterparts would do so regularly.

"I was often asked 'Why?' when I taught the Americans. They wanted to satisfy their curiosity before they agreed with what I was saying," Leung says.

In recent years, Leung has frequently returned to China to launch Wing Chun courses in the provinces of Fujian and Guangdong. There he found that the traditional master-apprentice relationship had also changed, and many young Chinese who come to learn martial arts now tend to ask questions, too.

Leung shared his decades of experience in his 2018 book, 60 Years of Wing Chun, which got a rating of 9.3 out of 10 on review site Douban for its relevance to younger practitioners.

And the guru who once used to shun the movie limelight has changed tack and embraced the idea for the sake of spreading the message about Wing Chun in his homeland.

During the shoot for The Grandmaster, the 2013 biopic about Ip Man, he recruited Tony Leung Chiuwai, the Hong Kong film star, as his student.

"I didn't expect him to take it so seriously," Duncan Leung says. "However, he really did, and the film turned out to be a success."

But he did not agree with everything in the production.

"In real Wing Chun, you don't have as complicated movements as you see in the movie," he says. "But the audience is king-so what choice do we have?"

The Grandmaster is considered to be one of the best kung fu films in recent years. It scored 7.9 points out of 10 on Douban, and was widely acclaimed by many moviegoers.

Duncan Leung's another wellknown student is Xu Haofeng, the Beijing film director known for his kung fu in art-house style, like The Master (2015).

"I learned a lot from Leung, who in turn learned it from Ip Man," Xu says. "If you really go deeper in kung fu, you will find it is essentially about morals and rituals, not violence. It can also hone a person's patience and wisdom."

To Xu's delight, his master agreed to be the martial arts consultant of his next movie, where he persuaded Duncan Leung to appear in a cameo.

Speaking at the forum, celebrated martial-arts blogger Wang Xiaolei, says: "In China, martial arts are connected with chivalry and justice, and also has cultural connotations with patriotism.

"However, kung fu is also often portrayed as something purely metaphysical and spiritual."

"I could feel Leung Shiu-hung's confidence as I watched his movements," says the online critic who also goes by the pseudonym of Liushen Leilei. "He taught people today to stand on solid ground."

Xiong Liang, a cartoonist for children's books, also shares his experiences of practicing martial arts while attending the forum.

"After learning kung fu, one may become more responsible about his or her work. Young people won't keep complaining and may think through their own problems," he says. "It will also help them to be more open-minded in interpersonal relationships."