The advice comes from Chetan Bhagat, the author of five blockbuster novels, including Five Point Someone (2004) which was turned into the hugely popular movie Three Idiots in 2009, breaking the box office records in India. The film also did well in Hong Kong.
The 38-year-old writer, who lives in Mumbai with his wife and seven-year-old twin boys, worked in Hong Kong from 1997 to 2008. It was here he wrote his first three books.
Five Point Someone is a reflection of Bhagat's university life. "It was a life when everybody was taught to take examination results too seriously, to a point they gave up their dreams; some even took their lives," he said.
He blames this on an educational system that puts too much emphasis on grades, and a conservative culture which suppresses creative thinking.
"Our system taught us if we fail an examination, we're no good, and we've failed life," he said. "But life isn't about one examination. In India, only 2 per cent of [applicants] will make it into [my former] university, which means 98 per cent won't. If we take everything, including failures, too seriously, we won't live a happy life.
"So, my motto is: Don't be serious, be sincere."
Five Point Someone was Bhagat's first published book, but not his first story. "My first story was published in the Young Post in 2003. In a way, the paper helped me along my journey of becoming a writer."
Very early on, he knew he wanted to be a writer, not a banker.
"The problem is nobody asks us what we want to do, so we don't ask ourselves that question either," he said.
But he didn't give up his dream. Bhagat worked at investment bank Goldman Sachs while he was in Hong Kong; when his colleagues played golf and mahjong, he would spend his time writing in the Central Library in Causeway Bay.
Now a motivational speaker, he has travelled to more than 50 cities in India. His message to students is straightforward: find your aptitude, set your goal, do what you want to do. Then, life will open many opportunities for you.
"People tell me they want a good life, and it means a good job and love. I tell them a good job isn't equal to [making] money, and love ... [means] finding the right partner. You have to do it in the right way."
All of Bhagat's five books have been, or will be, made into movies. In January, we will see a film based on his 2008 book The 3 Mistakes in My Life.
He is happy to be called "the biggest selling English language novelist in India's history" by The New York Times, but he refuses to think he is the best writer or be carried away by fame.
"I write for the people, not to become famous," he said. "I want to use my stories to arouse discussions on issues in society. I don't think I have the power to change the political system in India. But if people see the need to change our educational system after reading my books, then I feel I have contributed in some way."
After finishing his new book Revolution 2020 last year, he gave himself some down time.
"You need quiet time, to think," he said. "To turn off your phone, get away from the internet, go for a walk. If you never have time to think, you won't be creative."
"And read a lot of books - reading is the only way that fosters your imagination."
Bhagat is speaking at this year's Hong Kong Book Fair.