Rory McIlroy admits he found it "hard not to get frustrated" as he struggled to keep his emotions in check despite making a strong start to the US Open.
The Northern Irishman carded a three-under-par 67 to share the early lead at Brookline Country Club.
However, McIlroy slammed one club into a bunker and threw another down the fairway during his back nine.
"You're going to encounter things at a US Open that you just don't really encounter any other week," he said.
McIlroy, who warmed up for his latest attempt to secure a fifth major title by defending last week's Canadian Open, played his first 13 holes in two under before pushing his tee shot at the fifth - his 14th - into thick rough on the edge of the bunker.
Forced to take his stance in the sand with the ball well above his feet, the 33-year-old could only hack out into the bunker in front of him, prompting the four-time major winner to twice furiously slam his club into the trap.
"It's hard not to get frustrated because I'm walking up there going like, 'just come back into the bunker'," added McIlroy, who set the early pace with England's Callum Tarren, Sweden's David Lingmerth and American Joel Dahmen.
"The thickest rough on the course is around the edges of the bunkers. So I was sort of cursing the USGA whenever I was going up to the ball, but it's one of those things.
"It happens here, it doesn't really happen anywhere else. You just have to accept it.
"I gave the sand a couple of whacks because I'd already messed it up, so it wasn't like it was much more work for Harry (Diamond, his caddie), and then I just reset and played a decent bunker shot, and then it was really nice to hole that (par) putt."
'It's something to learn from'
McIlroy cut an exasperated figure at times during his opening roundHaving saved par at the fifth, McIlroy took the outright lead on four under with back-to-back birdies at the seventh and eighth but misjudged the approach to his final hole and tossed his club away in anger before finishing with a bogey.
"The margins are just so fine in this tournament, and I think you can sort of see that out there with some of the reactions," he said.
"Once I played our front nine in two under, the goal was to try to play this round without a bogey. I did that for 17 holes, which was great, and then I was sort of in two minds about what shot to hit on the second shot on nine and missed the green where you just can't miss it.
"I didn't do that all day. If I missed it, I missed it in the right spot, played for the fat part of the greens, and that's why I was frustrated, because you miss it left, it's a pretty simple up and down. You make par, you move on.
"But it's fine. It's something to learn from. (I'm) sitting here talking about the bad stuff when 17 of the holes were really good. I'm happy with the start."
McIlroy's last major win came in 2014, but the world number three followed his runner-up at this year's Masters by finishing eighth at the US PGA Championship.
"It has been eight years since I won a major and I just want to get my hands on one again," he admitted.