Tiger Woods insisted he was on the right track despite slumping to his worst ever score in the US Open at Chambers Bay.
Woods said on Tuesday he was willing to endure "short-term suffering for long-term gain" after coming into the event on the back of the highest score (85) and four-round total (302) of his career in the Memorial Tournament.
And the suffering continued for the former world number one with an opening round of 80 which contained eight bogeys, one triple bogey and a solitary birdie.
The 14-time major winner's previous highest score in the US Open was a 77 while still an amateur in 1996, although the 39-year-old at least retained his sense of humour.
"The bright side is at least I kicked Rickie's butt today," joked Woods, who saw playing partner and Players Championship winner Rickie Fowler shoot 81.
Woods, who has been making changes to his swing with consultant Chris Como, added: "(I'm) not very happy, that's for sure. It was a tough day.
"It's one of those things, just got to work through it. I'm trying as hard as I can to do it, and for some reason I just can't get the consistency that I'd like to have out there."
Asked if he was convinced he was on the right track, Woods said: "Yeah, I am, I am.
"I know when I do it right, it's so easy. It just feels easy to control, easy to do it, easy to hit all my shots. I just need to do it more often and build from there.
"I fought, I fought hard. And that was my number. I couldn't grind out any harder than that. So that's just the way I played - and unfortunately it was a high number today."
Woods, whose last major title came in the US Open in 2008, hinted that he was still suffering the effects of the back surgery which kept him out of the Masters for the first time in his career last year.
He added: "I didn't play much last year and I haven't played much this year.
"Knee surgeries are pretty easy compared to a back surgery, the recovery time. And for some reason, it's just a lot harder dealing with a nerve than a joint."
Woods had recorded just one round in the 80s as a professional before this year, but has now had three in the space of six events following an 82 in the Waste Management Phoenix Open and the 85 at Memorial.