"I don't know if there was ever a time in this country when I thought: 'Okay, it's slow enough for me. I need to go find another country where I could perhaps get that same feeling of exhilaration, that same feeling of satisfaction,'" he added.

Preston first lived in Shanghai in 1993, following his stint in Xi'an that lasted a few months. Being an adventurous person, he ventured beyond the restaurants in the Hilton Hotel on Huashan Road where he stayed and would explore the local dining scene.

He even had lunch with a local family in a tiny apartment.

"We would go there at lunchtime and sit on the bed," he chuckled. "But it was charming."

He also remembers how the Pudong area then was in its initial phase of development.

"People said Pudong was a big rice field. That was a lie," he said, while referring to a photo he took in 1993 that shows a half-completed Shanghai Oriental Pearl Tower from across the Bund.

As head of Boehringer Ingelheim China, Preston has managed the company's rapid expansion through projects including a biotech manufacturing and production facility in Pudong and an animal vaccine plant in Taizhou, Jiangsu province. As one of the leading projects in the city's innovation drive, the biotech manufacturing facility is aiming to become the first global provider of biopharmaceutical contract manufacturing solutions in China.

Preston is very proud of the project, which represented an investment of at least 100 million euros when it was launched in 2013. He pointed out that there was no regulatory pathway to guarantee that the plant would receive a license after being constructed during that time. Nevertheless, he managed to convince the company's headquarters in Germany to go ahead with the project because he "had faith in the Chinese government".

"That faith in government has stood me in a good place for many years," Preston said, adding that mutual commitment is the key for multinationals to survive and thrive in China.

When asked about his retirement plans, the seasoned businessman said he hopes to become a mentor for Chinese startups, which he said is the best way he could give back to the local community. Preston added that he does not plan on ever leaving Shanghai, which he admits still captivates him till today.

"One thing that is charming about the city is although we have the high-rises and it's very modern, you can still walk downstairs and find something very local very quickly," he said.

Preston also has a piece of advice for foreigners who are new to the city: "Never see something as wrong or right, but rather different. Embrace the Shanghainese of this city instead of being against them. As a foreigner, you have to fit in. You have to be part of it."