The key, he says, is to recognize and act on the opportunity.
Looking back, Day believes his father's death ultimately paved the way for his rise to become the No. 1 golfer in the world.
"I really honestly believe things happen for a reason in people's lives," the Australian told CNN's Living Golf show
at his Ohio base.
"When I lost my Dad I had an opportunity of going to a golf academy. If I didn't lose my Dad I wouldn't have had that opportunity. The life insurance money we got from his passing helped me go to the boarding school, the golf academy."
Lack of belief
Day grew up in relative poverty with his Philippines-born mum and two sisters in Rockhampton, Queensland, but was already a promising junior golfer before his move to Hills International College.
Despite his talent, his teenage years were beset by alcohol and behavioral problems.
However, he turned his life around and joined the pro ranks in 2006, and immediately targeted success in the US. His coach and mentor from the academy, Colin Swatton, became his long-term caddie.
Day slowly learned his trade before winning his first PGA Tour event in 2010. But shortly before making his Masters debut in 2011 he thought about packing it all in.
"I was not enjoying golf. I was not having fun, I was down on myself. I thought I was going to quit the game of golf," he said.
Instead, Day finished tied second at Augusta and added another second at the US Open two months later to suggest a breakthrough was just around the corner.
He had three other top-four finishes in majors in the next three years, but despite a fierce work ethic he couldn't quite take the next step.
"To be honest, I don't know if I believed in myself enough to win a major," he said.
Day was ranked fourth in the world going into the 2015 US Open at Chambers Bay but collapsed on the ninth hole, his 18th. He was slow to get up, and later announced he had been diagnosed with vertigo the month before. However, he returned the next day and ended the third round tied for the lead before finishing in a tie for ninth.
At the British Open at St. Andrews the following month, Day was devastated when he came up inches short with a putt which would have put him in a playoff.
Instead of bemoaning his luck, Day grasped the opportunity.
"Something switched," he said. "That's when I started thinking, 'I think I've finally paid my dues. I think I'm ready to win now.'
"It was more of a mental switch, a mental hurdle I always had in the back of my mind. I thought I had a good enough game to win, but I never really believed in myself. Something finally switched. I don't know how it happened, it just happened."
The following week Day won the Canadian Open, and backed it up shortly after by clinching his maiden major title, the US PGA Championship, by three strokes at Whistling Straits.
He celebrated on the course with wife Ellie and young son Dash, while their baby daughter Lucy has since accompanied the family to tournaments.
"We knew it was coming, we just didn't know when," Day said. "And then finally it happened and all this emotion, all the things you don't think about flash back to you in memories.
"I was thinking about my mum and my sisters growing up when we were poor, and now I'm playing in front of a lot people and winning a major championship."
Day's hot streak continued with two more big wins to finally become the world No. 1 in September 2015.
"To become the No. 1 player in the world has always been a goal of mine ever since I was a 13-year-old kid," added Day, who idolized Tiger Woods as a youngster and is now close friends with the 14-time major winner.
"The next day I thought I'd feel something different in myself. Maybe I'd walk around feeling I'm invincible, maybe I'd walk around going 'I made it.'
"Maybe all the stress and nerves and anxiety that built up through my career ... would have gone away and I can just go out and freewheel now. It hasn't.
"All the anxiety, the stress, the pressure is still built up inside of me because I don't want to play bad golf.
"I can't miss a beat. If I really want it, there's no one in this world that's going to beat me."