 -- Mitt Romney admits he's "haunted" by the verbal gaffes he's made during his second run for president but says he's the victim of a media environment that encourages "spontaneous" actions, yet pounces on mistakes.

In an interview with the Wall Street Journal's Peggy Noonan, Romney acknowledges that he's forced himself to "be a little more careful in what I say" after mistakes that "make me want to kick myself in the pants."

Among his gaffes, Romney cites his comment at a New Hampshire luncheon in January when he said, "I'd like to be able to fire people." He said he meant health care companies that provide inadequate services, but the remark has been used against him in Democratic attacks ever since without that kind of context.

In the current media environment, Romney says, "you will be taken out of context, you'll be clipped, and you'll be battered with things you said."

"I have to think not only about what I say in a full sentence but what I say in a phrase," Romney tells Noonan. "The media always says, 'Gosh, we just want you to be spontaneous,' but at the same time if you say anything in the wrong order, you're gonna be sorry!"

The presumptive Republican nominee insists he's enjoying his time on the campaign trail, but concedes he has off days. Asked if he wakes up in a "good mood," Romney admits that doesn't always happen.

"The only time I'm unhappy is if I've done something that hurt the prospects for the success of our effort," Romney says, though he adds he doesn't remember the last time he woke up unhappy. "Sometimes you're disappointed, but it's mostly disappointment with myself that causes me to be most concerned. This for me is not my life, meaning I don't have to win an election to feel good about myself."

Asked if he loves the game of politics, Romney says he likes the "competition."

"I think the game is like a sport for old guys. I mean, you know, I can't compete in competitive sports very well, but I can compete in politics, and there's the—what was the old ABC 'Wide World of Sports' slogan? 'The thrill of victory and the agony of defeat,'" Romney says. "The only difference is victory is still a thrill, but I don't feel agony in loss."

The presumptive Republican nominee tells Noonan that he's keeping a personal diary of his 2012 bid on his iPad, which he updates every two or three days so that years from now he can "remember what it was like… the feelings, the ups, the downs, the people I meet and the sense I have about what's going to happen."

"It's kind of fun to go back and read, as Ann and I do from time to time," Romney says.

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