Shawn Mendes at iHeartRadio Music Festival 2015: The Biggest Lesson Taylor Swift Taught Him

Shawn Mendes has a hit in his latest single, “Stiches,” and he’s itching to get more new music out to his fans. The singer-songwriter -- who’s been opening on select dates of Taylor Swift’s 1989 tour -- spoke to Billboard backstage at the 2015 iHeartRadio Music Festival, where he performed “Stitches” onstage with Hailee Steinfeld on Saturday, Sept. 19.

Shawn Mendes: 'Stitches' is 'A Very Good Bridge' to New Music

“When you’re songwriting and stuff, you just hate your old stuff,” he admitted. “All you want to do is release the new stuff because that’s, to you, so much better and you just want to get that out there. But I think you’ve got to take your time. I’m excited for when we eventually do release it to see reactions.”

Besides being eager about the new music that’s to come, though, Mendes has had plenty of exciting experiences in 2015 so far.

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“I think the best part [of the last year] has just been the growing experience. I mean, I’ve been learning so much,” he said. “I had the chance to go on the biggest tour in the entire world [Swift’s1989 tour] and see the biggest act in the entire world do her thing every night and learn from that, and learn from her style and the way she is with people.

“I think the biggest thing I’ve learned is there’s no amount of success that allows you to stop working hard, or, you know, kind of like brush off interviews or whatever your promo [responsibilities are],” he continued. “She’s just seems to always be working, no matter how successful she is, you know. It seems like she has it all, but yet she acts like she’s still on the grind, which is so cool."

Check out the full interview clip above.