Karlie Koss may be a tall, gorgeous, successful model—not to mention a card-carrying member of Taylor Swift's #BadBloodSquad. But in a recent video posted to her Klossy YouTube page, the former Victoria's Secret Angel confessed that confidence hasn't always been her strong suit.

"As a kid, I was really tall and skinny and awkward and gangly—and I wasn't confident," Kloss, 23, said, while also sharing some adorable grade-school pics. "I've always been very open with my friends and family, but when it came to getting in front of a crowd, I always used to be very self-conscious and shy. I would go into a shell and just be very quiet."

As a catwalk staple at fashion week shows in New York, Paris, and Milan, Kloss has clearly mastered her fears, and she credits ballet for helping her do so.

"One of the first ballet recitals that I danced in pointe shoes, I was so nervous. I didn't want to let [my family] down. I didn't want to let myself down!" she explained. Her solution: "I learned to cope [by taking] that anxiety—that adrenaline—and [pouring] it into something productive. What can you do to best prepare for that moment? So when it came to showtime…I knew that I did everything I possibly could to feel amazing and just perform."

That said, Kloss knows first hand that no amount of preparation guarantees a smooth result. (She even called out that time in 2010 she slipped during a Fendi runway show!) But, as she also points out, "All you can do is do your best. Even when you make mistakes, sometimes those can be the most important experiences to learn from."

...I haven't been this nervous in years! ?????????????? #firstdayofschool

A photo posted by @karliekloss on Sep 2, 2015 at 4:37pm PDT

The model also shared her next big excited—and nerve-wracking—moment: her first day going to school at NYU, which she's also talked a bit about on her Instagram page. Sharing a photo of herself standing outside a university building on Wednesday, Sept. 2, Kloss wrote, "I haven't been this nervous in years!" with the hashtag #firstdayofschool.

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