Johnson won the U.S. Open in June, racking up his first major championship, and followed that with a victory two weeks ago at the WGC Bridgestone Invitational, something he accomplished by overtaking Jason Day, the 54-hole leader.
At a press conference in Troon on Wednesday, he was asked if he felt like the best player in the world right now.
"I always feel like the best player in the world," Johnson said, smiling a little.
It was a typical answer. Day talked at his own press conference on Monday about the stress of being the world number one. Johnson was asked if he would feel the same kind of stress if he were number one.
"I don't know," he said, looking slightly puzzled. "I'll let you know when I get there."
Johnson can be serious. He is one of the high-ranking golfers who won't play at the Rio Olympic Games, a decision he said was based on his unwillingness to expose his family to the Zika virus carried by Brazil's mosquitoes. He would have played in Tokyo, he said, the site of the 2020 Olympics.
"I know the risk is very low," he said. "But if something were to happen, I'd never forgive myself for that."
Johnson is aware Americans have won the last six Opens played at Troon but doesn't think nationality had anything to do with their success.
"If you look at the winners the last few times, they're all good players, all good putters," he said. "That's the key in every major. It has no difference in whether you're playing here or in the U.S. ... you've got to putt it well."
Johnson is a very good putter, but he is better known for his performance at the other end of the scale - hitting gargantuan drives, the kind John Daly in his prime might have envied.
Some people think links courses like Royal Troon negate the advantage long drivers usually have.
With humps, bumps, hills and hollows, pockmarked by deep bunkers and festooned with punitive rough, links can swallow errant drives but Johnson is not worried.
"No, links courses are just how they are," he said. "Their defence is the bunker, so for me it's all about just navigating the bunkers ... if you can stay out of the bunkers this week, I think you're going to do pretty well."
(Reporting by Larry King; Editing by Rex Gowar)
