Before he became one of India's best-selling authors, he was just another IIT-IIM graduate chasing a successful corporate career. Chetan Bhagat was an investment banker juggling a demanding career in Hong Kong at Goldman Sachs. What many don't know is that the story that would eventually inspire one of Bollywood's biggest blockbusters was written while he was still working in the corporate world, often during breaks between banking assignments.Today, the author is known for books that have sold millions of copies and inspired several hit films. But his path from engineering student to banker and eventually bestselling author was anything but conventional.From IIT Delhi, IIM Ahmedabad to Goldman SachsChetan Bhagat grew up in a Punjabi family in New Delhi. His father served as a lieutenant colonel in the Indian Army, while his mother worked as a scientist at the Indian Agricultural Research Institute.A bright student, Bhagat earned admission to the prestigious IIT Delhi, where he completed a degree in Mechanical Engineering in 1995. He later pursued an MBA in Marketing from IIM Ahmedabad, graduating in 1997. Years later, the institute honoured him with its Young Alumni Achiever's Award in the Arts and Entertainment category.After completing his studies, Bhagat entered the world of finance and began working as an investment banker. He joined Goldman Sachs in Hong Kong and later reportedly moved to Deutsche Bank in Singapore.Writing a novel while working as a bankerLast year, during a conversation with entrepreneur and podcaster Kaushal Lodha, Bhagat recalled how difficult it was to balance his banking career with his dream of becoming a writer.According to Chetan, he would often write whenever he found time, whether at home, in the office or during weekends. He remembered how one file on his laptop contained investment banking documents and term sheets, while another contained stories about life at IIT. That manuscript eventually became Five Point Someone.Bhagat revealed that the novel was not an instant success. In fact, several Indian publishers rejected the manuscript for two years. He said many were unsure about the unusual title and concept. Despite the setbacks, he continued trying until the book finally found a publisher.The book that inspired 3 IdiotsPublished in 2004, Five Point Someone felt relatable to young readers through its story about engineering students dealing with academic pressure and expectations.A few years later, the novel 'loosely' inspired the blockbuster film 3 Idiots, directed by Rajkumar Hirani and starring Aamir Khan, R. Madhavan and Sharman Joshi. The coming-of-age comedy-drama became a cultural phenomenon and earned reportedly more than Rs 400 crore worldwide, making it one of the most successful Hindi films of its time.The controversy around credit and compensationIn 2020, Bhagat revisited the long-running discussion about 3 Idiots and its connection to his novel. He took to X (formerly called Twitter) and wrote, "Many know this, for those new here. 1) 3 Idiots was based on my novel Five Point Someone and my story. 2) The film won every story award that year.3) I was not given any of those story awards. They took them all.4) As a powerless newcomer I was bullied and was deeply affected"Bhagat has also spoken openly about the financial side of the adaptation. In the same interview, he revealed that he initially received Rs 1 lakh for the rights to the story, along with a clause promising an additional Rs 10 lakh if the film became successful. After the movie turned into a blockbuster, the promised bonus was paid, bringing his total earnings from the deal to Rs 11 lakh.However, Bhagat said he does not regret the agreement. Looking back, he felt it was a fair deal for a newcomer at the time, especially when no one could predict the scale of success the film would achieve.From banker to bestselling authorChetan Bhagat eventually left investment banking in 2009, walking away from a lucrative career to focus entirely on writing. The decision paid off. Over the years, he has become one of India's most successful authors, with more than one crore copies of his books sold.