Taylor Swift has nightmares about playing to empty venues.
The 26-year-old superstar - who has just wrapped her '1989' world tour - admitted she has times where she worries that people won't want to see her perform.
She said: "I have nightmares where nobody shows up and nobody wants to see me perform at all. I would just cry. I would just sit on the stage and cry."
Taylor also revealed that despite her success she is prone to days of self-doubt but insisted that the roar of the crowds at her gigs always cheers her up.
She said: "My friends and I talk about this all the time; just being in our twenties, you don't know what it's going to be like when you wake up. Not every day is perfect. It's not always sunshine in my brain and sometimes I just wake up with a bad attitude. But I hear people screaming and a switch flips and I'm excited."
Taylor is renowned for her squad - a group of famous friends including stars such as Selena Gomez, Lena Dunham, Karlie Kloss, Cara Delevingne, Blake Lively, Lorde and the Haim sisters - and she admitted the friendships are so important to her because she didn't have many pals growing up.
Taylor - who called Este Haim her funniest friend and called Lorde the ass-kicker of the group - told Zane Lowe in an interview with Apple's Beats 1 Music: "It was hard to foster friendships when I was young and I think that's why friendships are such a huge part of my life now. When you're in school anything that makes you different makes you weird and anything that makes you weird makes you off limits like 'Don't invite her'.
"Nowadays, when I meet someone at an event or something and we hit it off, we keep in touch, and over time all of us ended up being a group that love each other and support each other."
Referring to having her friends join her on stage during her shows, she said: "It would be weird to not include my friends. These were the people who helped me get to this point where i could make this album. These were the ones who were like, 'Don't listen to your label. Do whatever you want'...And so when this album came about, I had my friends walk down the catwalk because it was fun! The tour became a way for us to meet up all over the world."