When Goh Chok Tong made his first trip to China in 1971, he described the experience as like "going to an alien country".

Singapore's emeritus senior minister and the man who succeeded Lee Kuan Yew to become the country's second prime minister (1990-2004) said, "China was a totally different country back then."

Sitting in the West Drawing Room of The Istana, the ornate colonial home of former British governors set in lush green gardens and now the office of Singapore's president, Goh described how it took three to four days to get from Singapore to Beijing in the past.

"You flew from Singapore to Hong Kong, stayed overnight. Then took a train to Guangzhou where you also stayed overnight, before flying to Beijing if the weather permitted," he said.

He described how men and women wore Mao suits, how workers were assigned places of work, and bicycles ... bicycles everywhere. Cities were run down and the people poor.

Goh said China back then was still halfway through the "cultural revolution" (1966-76) and its economic impact on the world was "minimal".

Since Deng Xiaoping introduced his reforms 40 years ago, the opening-up of China has had "a big impact on the world, positively", Goh said.

"Men and women wear the latest fashions and cars have replaced bicycles. Cosmetic sales flourish. People now travel freely in search of jobs, motivated by profit and wages rather than being bound to assigned places of work. Social habits have changed."

In terms of education, Goh said the biggest change has been in the large number of students now going overseas to study.

"English is now more widely spoken. Admission to university is now based on academic merit rather than ideology," he said.

"This has raised the standard of education, intellectual discourse and research."

He said in diplomacy, China is now more active and has a presence in "all parts of the world".

"Before, it conducted diplomacy from behind a 'bamboo curtain', so-called by Western journalists."

Asked whether he had thought China would emerge as the great nation it is today, Goh thought about the question, leaned back in his chair and said, "Frankly, no."

"My father came to Singapore (from Yongchun county in Fujian province) at the age of 7. I grew up in Singapore so my knowledge of China at that time was one of poverty. My grandmother would describe how cold the winters were and how difficult life was in China. My grandmother sent old clothes to relatives in China. So my impression was one of a poor country."

Goh's first meeting with Deng was in 1978 when he was part of an official Singapore delegation led by Lee. The meeting was in November, just one month before Deng announced his historic reform and opening-up policy that would propel China into the 21st century as an economic powerhouse and a major global power.

"What was my impression? Very positive," Goh said.