Taylor Swift's Eras Tour has captivated millions of fans across the United States, consistently selling out stadiums and taking cities by storm, with the singer at the center of the spotlight on and off the stage.
Since the start of the tour in March, Swift fans, or Swifties, have shared friendship bracelets and connected online to share their concert experiences, but many said they were surprised to find something strange in common.
Throughout the nationwide tour, many fans said they felt like they were left in a "lavender haze" after Swift's concert and had trouble remembering specific details of the eventful night, almost as if there was a "blank space" where their memories of the show should be.
"Thinking back on it, I don't have any one specific memory I can recall, it's more like an overall memory of the event," Danielle Lake-Patterson Dickson, a concertgoer and Swiftie, told ABC News.
Dickson and other concertgoers described having "post-concert amnesia," which is not an official medical term but described this reported experience, according to Dr. Leah Croll, a board-certified neurologist and assistant professor at Temple University.
"'Post-concert amnesia' isn't a medical diagnosis," Croll told ABC News. "It's actually just a descriptor for what these fans are saying they're experiencing."
Now with Swift's highly-anticipated concert film,"Taylor Swift: The Eras Tour," hitting theaters Oct. 12, many fans are wondering if they will encounter the phenomenon again, or for the first time if they didn't attend one of the singer's concerts in person.
Experts say it's possible, but less likely, and may actually help people who don't remember details from the concert store more specific memories of her performance.
Post-concert amnesia isn't dangerous but could be disappointing for someone who wants to remember certain details of a special event that they can't recall.
"It's the same reason why people often say they can't remember the details of their wedding day, because they were way too busy being in love and talking to a million people at their party and taking in the scenery and the food and the music," Croll said.
The large crowd, noise level, excitement, and effects like strobe lighting and fireworks at large-scale concerts by superstars like Swift and Beyoncé make storing specific memories of the event difficult for the human brain.
"Your brain can only process so much information at one time. It's kind of like a computer in that sense. So, you're being hit with all of these stimuli, and something has to give, and a lot of the time that something is memory storage," Croll said.
Dr. Soha Salman, a psychiatrist, said she experienced "post-Eras Tour amnesia" and believes there are some common Swiftie characteristics that may contribute to this phenomenon.
Swift has been a singer-songwriter in the public eye since she was a young teenager, releasing her debut album when she was just 16 years old.
Since then, Swift has centered her work around writing about lived experiences that deeply resonate with her fans. Swift's songwriting has made her not only more relatable to her fans but has also connected her to fans on a deeply emotional level for nearly two decades.
"Listening to her go through those experiences, listening to her music -- as fans, maybe we're going through something similar," Salman told ABC News. "That's played a huge role, I think, in the emotional connection."
Dr. Nathan Carroll, associate chief resident in the department of psychiatry at Hackensack Meridian Jersey Shore University Medical Center, said it also can't be ignored that Swift's tour took place in the context of people coming out of the coronavirus pandemic, when many people faced hardships.
"I think this concert was very meaningful to a lot of people in many different ways," Carroll told ABC News.
Experts say an intense emotional experience can confuse the brain and set off the same neurotransmitters that respond to highly stressful situations and act to inhibit memory formation. But some good news for Swifties planning to watch the Eras Tour movie is that there's far less going on in a movie theater than at a concert, so it's easier for memories to be made.
"It's hard to imagine a movie eliciting that same stress response on the same scale that a concert would," Croll said. "Maybe for some people who are really diehard fans, I could see it happening, but I don't think the average Taylor Swift fan would experience [post-concert amnesia] with the movie."
Movies are often more focused on one thing going on at a time and center the audience's attention which can help memory formation, and if nothing else, someone can watch a movie again-and-again to try to remember more details.
Experts says the best way to prevent post-concert amnesia is to be present in the moment, remember that being under the influence of substances can also impair memory formation, and to go into the event rested and well hydrated. Taking deep breaths can be calming, but there's no harm in being excited.
Experts say it's also important to manage expectations. The brain isn't meant to store every single detail of big events. As Swift writes in her song "You're on Your Own, Kid," "Make the friendship bracelets, take the moment and taste it, you've got no reason to be afraid."
Salman and Carroll both said they are preparing to publish research on this fandom phenomenon and join a larger movement in the scientific community to systematically study the "Swiftdom," evidenced by an upcoming academic conference called Swiftposium 2024, organized by a number of universities across Australia and New Zealand, which will center around themes of Swift's songs, including fandom, according to the event website.
Dr. Jade A Cobern, M.D., MPH, licensed and practicing physician, is a member of the ABC News Medical Unit.