Gupta was just 22 years old when he joined Citibank India and was sent to a remote Kolkata branch to manage a team of around 30 clerical staff in their 40s and 50s.
There, he thrived by both respecting and listening to his colleagues, he said.
It was the early 1980s, and labor unions were at their prime in the then-communist state of West Bengal. In other words, employees could have gathered powerful backing if they disliked Gupta's management plans.
"Here I am, this 22-year-old green kid, and I've got to give instructions to these 45-year-old hardened union people and get them to relate to what I thought they should be doing," Gupta said. "The unions were very powerful and used to intimidate the managers both physically and verbally."
Gupta, 58, said he quickly learned he was able to build a rapport and get his colleagues on his side by respecting and listening to them. "By being able to win over people personally, you can then guide them and take them professionally to paths that they otherwise might be reluctant to do."
Gupta, who today runs Southeast Asia's largest bank, described the achievement as a "seminal moment" in his career.
Shortly after, he was put on Citibank's labor relations committee for India. At that time, he was the only 24-year-old working on the management side among a team of 40-year-olds.
"That came from my ability to work with the people and the unions really well at a very early age," he said.
Like this story? Like CNBC Make It on Facebook!