La Jolla - Jon Rahm is still getting to grips with the meteoric rise sparked by his victory in the 2017 Farmers Insurance Open.
The 23-year-old Spaniard's first US PGA Tour title here last year pushed him into the top 50 in the world rankings.
He arrived at Torrey Pines for his title defence ranked number two in the world.
"It's kind of hard to process it, to be honest, because I live my day-to-day life with my girlfriend and my team around me and they don't change their behaviour based on what I do," he said Tuesday.
"I got a little bit of it when I went back to Spain and I realized what a huge deal my year had become over there, but I feel like the less I think about it, the better."
Rahm's win at Torrey was followed by back-to-back top-five finishes in World Golf Championships events.
Then came wins in the European Tour's Irish Open and season-ending DP World Tour Championship.
He supplanted three-time major winner Jordan Spieth as number two in the world on Monday after winning the CareerBuilder Challenge in La Quinta, California, at the fourth hole of a sudden-death playoff against Andrew Landry.
Rahm capped his final round at Torrey Pines last year by rolling in a 60-foot eagle putt, but he said the key to his round was his second shot out of a fairway bunker at 13, which left him an 18-footer for eagle.
"If I don't put that ball on the green, which is actually a lot harder than making that putt, the back-nine charge would have never happened and this year might have never happened, so that shot is the one that made everything possible," he said.
Rahm is the fourth Spaniard to rise as high as he has in the world rankings, following in the footsteps of Seve Ballesteros, Jose Maria Olazabal and Sergio Garcia.
He said he won't be focusing his attention on seizing the number one spot from American Dustin Johnson.
"I'll try to focus more on what's going on this week rather than what comes with it if I win," he said.