Jungkook says he thought he was so cool during the hat performance on BTS' debut stage

BTS looked back at their debut on Mnet's 'M Countdown.'

On January 3, 'M Countdown' aired a special for the 600th episode. Idol groups who had their debut on the music show recalled the unforgettable moment.  The boys had their debut on 'M! Countdown' back on June 13, 2013.

Jimin first said, "It really felt like I'm debuting. 'M Countdown' made it feel official." V added, "It was a stage where I was able to show the world that I exist." j-hope commented, "People were reacting 'ohhhh' to our performance."

Jungkook mentioned the hat performance of "No More Dream", and said, "Jimin hyung threw the hat and I caught it. It was thrilling because it was the first time I ever received loud cheer." He timidly admitted, "I thought I was cool."