John Mayer on the Song About His Ex That He Can't Play Live: 'I Don't Think I Could Make It Through It'

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John Mayer writes from the heart.

The 39-year-old singer-songwriter has had his share of romances, and on his new album, The Search for Everything, there’s one song that particularly gets to him.

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“Where this song comes in was I was really, really sad, like the kind of sad …everyone’s there once in their lives, hopefully only once,” he told SiriusXM’s Buzz Brainard in a new radio interview on The Highway. “I was sad about everything. And this song idea came to mind, and it was like, ‘Never on the Day You Leave.’ I don’t know where it came from, but I just thought, all at once it came out full-cloth, and the song was written in 20 minutes.”

Though the words came quickly, there was one lyric in the song that really got to Mayer.

“There’s a line in there that’s so brutal because it’s so true,” he said. “‘She’ll fight for you like hell, then force herself to like some other man.’ That’s what women do. They show up 100 percent. There’s a time they are there 100 percent with everything. And then, at some point for whatever reason, not making a judgement, you or someone else says, ‘Nah.’ And what they force themselves to do to get over you is so transformative for good and bad that you will never see that whole person again.”

The line proved hard for the accomplished singer to even record, let alone perform live.

“Every time I sang that line, I would cry in the middle of that line. It took me days and days and days to be able to sing that line for the record and get through it without crying,” he recalled. “I can’t play the song live because I don’t think I could make it through it. Like, I haven’t played the song live, I don’t think I can. I don’t like to think about it.”

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Mayer didn’t specifically name the ex in question, but he did say that he recently ran into her.

“It was very amicable. And I had this beautiful moment where I said, ‘A lot of it’s me. A lot of it’s in my head, you know,’” he shared. “Something happened to me and it’s just the way I work, the way my mind is, and I took it really hard, and that took a long time to be able to admit.”

Mayer has had lots of famous exes, including Jennifer Love Hewitt, Taylor Swift and, most recently, Katy Perry.

The pop star later moved on with actor Orlando Bloom, but the two split earlier this year. Over the weekend, however, Perry and Bloom were spotted together again at an Ed Sheeran concert.

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