Songfacts®:

• There has been much speculation that this song is about rock musician John Mayer, with whom Taylor recorded a duet, Half Of My Heart, in 2009. Rumors circulated that the pair were dating for a short period after they worked on the track. Swift, who turned 20 in December 2009, won't outrightly acknowledge the subject of the song, but these lines hint that it may well be about Mayer, who is 12 years her senior:
  
  It was wrong
  Don't you think nineteen's too young
  To be played
  By your dark, twisted games
  When I loved you so
  
  Mayer has a long list of scorned former girlfriends, including Jessica Simpson and Jennifer Aniston. His famous heartbreaking reputation is also possibly addressed here, when Taylor sings about the guy who is known for "all the girls that you run dry."
• Asked if the song was about Mayer by People magazine, Swift responded; "A lot of times when people's relationships end, they write an email to that person and say everything that they wish they would have said. A lot of times they don't push send."
  
  "This was a tough one to write," she added," and I guess putting it on the album was pushing send."
• A "Dear John" letter is an old expression referring to a wife or girlfriend writing to inform him their relationship is over, usually because the author has found another lover. It is possible the song takes its title from the phrase but unlikely as Taylor is nothing if not extremely literal in her lyric writing.
• During an appearance on the November 1, 2010 episode of The Ellen DeGeneres Show, the chat show host asked Taylor outright if this song is about John Mayer. After dancing around the question for a while, she eventually replied, "I'm still going to continue to write about my life and I guess people are going to continue to speculate about it, and I'm going to continue to never tell them what the song's about."
• Though Swift has never confirmed the scathing song is about John Mayer, it has still upset the rock musician. "It made me feel terrible," Mayer told Rolling Stone. "Because I didn't deserve it. I'm pretty good at taking accountability now, and I never did anything to deserve that. It was a really lousy thing for her to do."
  
  The timing couldn't have been worse as the release came immediately after Mayer had experienced a backlash following a couple of controversial interviews. He contended that he was unaware of Swift's true feelings for him following their relationship until he heard the song and wondered why she had to be so mean. "I never got an e-mail. I never got a phone call," he said. "I was really caught off-guard, and it really humiliated me at a time when I'd already been dressed down. I mean, how would you feel if, at the lowest you've ever been, someone kicked you even lower?"
  
  When asked about the song's lyric, "Don't you think I was too young to be messed with?" Mayer responded, "I don't want to go into that."
• Speaking with the November 2012 issue of Glamour magazine, Taylor hit back at Mayer's comment that it "really humiliated me" when he heard this song. "How presumptuous! I never disclose who my songs are about," Swift responded, adding that she opted to keep herself in the dark about his comments. "It's not that I'm this egomaniac and I don't want to hear anything negative," explained the star, "because I do keep myself in check. But I've never developed that thick a skin. So I just kind of live a life, and I let all the gossip live somewhere else. If you go too far down the rabbit hole of what people think about you, it can change everything about who you are."
• Taylor Swift rarely performs the song live. She sang "Dear John" for the first time in over a decade during the Minneapolis leg of her Eras tour on June 24, 2023. The previous time Swift performed the song in concert was during her March 17, 2012 show in Auckland, New Zealand.