"Who else would I be thinking about?" he said. "And by the way, it's a testament to the fact that I have not dated a lot of people in the last five, six years. That was my only relationship. So it's like, give me this, people."
Lyrics include "I still keep your shampoo in my shower / In case you wanna wash your hair / And I know that you probably found yourself some more somewhere / But I do not really care" and "Still like the letters in your name and how they feel, babe / Still think I'm never gonna find another you / Still like to leave the party early and go home, babe / And don't you know, babe / I'd rather sit here on my own and be alone, babe."
Larry Busacca/Getty Images for Sony Music Entertainment
The song is a track from Mayer's new album The Search for Everything, which contains other breakup songs.
"There were times when tears came out of me, and I went, OK, John, this is not about an on-again, off-again relationship. This is something more profound," he told The New York Times.
He told the outlet that since his and Perry's split, he has hardly dated, although he has used a dating app, adding, "It's just lot of chatter...we all talk to the same people. There are very few people actually meeting up."
He also talked about wanting to settle down with someone and start a family.
"I wish there was somebody to throw me the 40th," he said. "I want the baby with the protective earphones" [by the side of the stage]."
The singer himself is believed to be the subject of the song "Dear John" by another one of his exes, singer Taylor Swift , who is known for releasing songs about heartbreak. The two reportedly dated for several months, starting in 2009, when she was 19. She has never confirmed the song's subject manner officially.
In 2012, Mayer told Rolling Stone he felt "really humiliated" by her song, which he believes is about him and contains lyrics such as "Don't you think 19 is too young to be played by your dark twisted games?"
"How presumptuous! I never disclose who my songs are about," Swift told Glamour magazine in response to Mayer's comments.