Lee has since then served in government for almost three decades before he retired in 1988. In 2005, he was invited by Prime Minister Lee Hsien Loong to attend the 50th anniversary of the Bandung Conference. But to him, there's "no second Bandung Conference" like the one in 1955.

"China brought up the Five Principles of Peaceful Coexistence at the Bandung Conference, which was very good," he said.

"During the conference, Zhou got the opportunity to explain to other countries that China was not trying to subvert their political power, and it was the first time China established connectivity with countries in the world. Zhou made a great contribution to this."

It was not until 20 years later when Lee and Zhou met again. In 1975, Lee, the then minister of state for foreign affairs, visited China with Singapore's foreign minister S. Rajaratnam.

Zhou, who was suffering from cancer at that time, met them in Beijing where he was hospitalized. To his surprise, Zhou "had a really remarkable memory."

"He said, 'Oh, we met in Bandung and you had interviewed me," Lee said and smiled.

That trip later kicked off bilateral communications between Singapore and China.

Since the first trip to China in 1975, Lee has visited China more than 100 times, either as a politician, diplomat, tourist, businessman or antique collector. He has witnessed the dramatic changes of China.

"I admire Xi Jinping's axe on corruption, it will do great good to China," Lee said.