Singh, who left a full-time show-business career at Mediacorp in 2014 to devote more time to his family, had doubted his ability to write a book until three different publishers approached him. Hearing from the third, Armour Publishing, was 'God's way of hitting me on the back of the head', he says. Dismissing the offer of a ghost writer, he decided to write about what he knew best - his own life.
"People know me as a funny guy with no cares in the world," he says. "But there are other facets of my life. I've been through hard times, depression. What people see on television is made up. We (celebrities) still have to brush our teeth in the morning and put our pants on one leg at a time."
The actor and host, who is best known for playing Singlish-spouting contractor Phua Chu Kang on TV, has also been in local films such as One Leg Kicking (2001), Just Follow Law (2007) and last year's Young And Fabulous. He is married to Ngee Ann Polytechnic lecturer Melissa Wong, 47, with whom he has three children - Gabrielle, 20, Elliot, 16, and Mikaela, four.
Singh's book has its emotional segments, but is nevertheless filled with the kind of humour one might expect of the iconic funnyman. He and his two younger sisters grew up in the back room of the bank where his father worked. Their mother cared for other people's babies to earn extra income. Money was tight. In his pre-university days, he got a daily allowance of 40 cents and was shocked to discover that his classmates were getting $5 to $20.
As a teenager, he spent his weekends guarding the bank while his father took a break. To entertain himself, he invited his friends over to play table tennis on the bank's upper floors or rode his father's motorcycle around the waiting room. As a child, he was always getting into scrapes. Once, inspired by television show Hawaii Five-O, he vaulted a chain at the former National Library and dislocated his arm at the shoulder. A sinseh popped it back into the socket and he vomited from the shock into his mother's cupped hands.
He also discusses his experiences with epileptic fits - which he learnt to keep at bay by never allowing himself to go hungry - and the deaths of his parents, whom he was very close to. He lost his mother, the illegitimate child of a Chinese woman and a Japanese soldier who was adopted by an Indian couple after World War II, to cancer in 2001. On the day of her funeral, his father, who was Punjabi Indian, was also diagnosed with cancer. He died two years later.
Singh found this the most difficult part of the book to write. He recalls how while his mother was undergoing chemotherapy, he had to continue to do comedy. "If only I'd been doing drama," he says. "I would have been Best Actor every time, my tears would have been flowing so easily."
He lashed out at paparazzi at his parents' funerals and remained depressed for four years afterwards. During a Phua Chu Kang musical for the President's Star Charity, he broke down crying backstage because a line in the script about a parent's death triggered him.
Singh, who is now looking into making a film abroad, hopes his parents would have been proud of him for writing the book, had they lived to see it. "My whole life I've tried to make them proud of me - I was never the brightest in my family, you know - so I hope they would have been proud."
What Was I Thinking? by Gurmit Singh ($20.33) is available at Popular, Books Kinokuniya and www.armourpublishing.com.