Golf's newest sensation has the mantra 'why not?' on his golf balls. It was inspired by his desire to to be a good dad.

• Michael Block became an overnight sensation for his play at the PGA Championship.
• Block uses the mantra "Why not?" to gain confidence and has it written on his golf balls.

Michael Block went from local golf pro to overnight cult hero, a remarkable journey that was fueled by inspiration he found in fatherhood.

Block, a 46-year-old local PGA professional, was the biggest story at the PGA Championship, where he went toe-to-toe with the world's best golfers, many much younger than him. While his 15th-place finish as a long-shot underdog was great, his happy-go-lucky personality made him an instant star among golf fans.

Being a golfer with a positive attitude did not come naturally to Block, but his desire to be a good dad did, and the latter eventually led to the former.

Block, who has the phrase "Why not?"on his golf balls, explained the origin of his inspirational mantra before the 2014 PGA Championship at Valhalla Golf Club in Louisville, Kentucky. Block said it started as a happy face just after his kids were born.

"I was a very frustrated golfer, as many are," Block told the media during a press conference. "I would get very frustrated on the golf course. And I just had children, two boys ... and I didn't want to demonstrate this to my boys whatsoever. I wanted to be a good role model to my children. So I actually started writing happy faces on my golf ball just to try to get me in a good mood even when I did not execute a shot."

Block said that the happy faces felt silly, so he switched to a simple question mark to remind him to be positive on the course.

"One of my main things over the golf ball is full commitment, and the only way you're going to have full commitment is if you have full confidence in yourself in executing the shot," Block said. "And the way that I do that mentally is thinking why not; why can't I execute this shot perfectly? Why can't I make this shot? Why can't I make the cut in a TOUR event, and why can't I compete in a major championship?"

As for how he went from a question mark to the written-out phrase "Why not?" that came from one of the biggest moments of his career prior to this week's PGA Championship.

In 2007, he was in a playoff at a qualifier with a spot in that year's US Open on the line. According to E. Michael Johnson of Golf Digest, Block's caddie mentioned that if he made a 22-foot putt, he would be in the US Open.

Block said to himself, "Why not?" and then sank the putt.

Block later explained at the 2014 PGA Championship that "Why not?" is now his mindset anytime he is on the golf course, whether it is a local event, a PGA Tour tournament, or a major championship.

"I take the same mentality every time I'm over the golf ball now," Block told the media.

Block's commitment to his family is also why we won't see him grinding on the course every week, looking for a shot on the PGA Tour.

After finishing his final round on Sunday at the PGA Championship, he said there would be no tours in his future. Instead, he wants to compete when he is in a tournament and then go back to his club and hang out with his family.

Besides, he still gets to compete from time to time.

This week's tournament was his 25th career PGA Tour event and his fifth career PGA Championship. He has also played in two US Opens. Block's T15 finish this week earned him an automatic spot in next year's PGA, and he was also invited to play in this week's Colonial.

Can Block breakthrough and eventually win one of these tournaments? Why not?