Dynamic Duo appeared on SBS powerFM's 'Kim Chang Ryul's Old School' on November 24, where they revealed how they were when younger.

The DJ said, "You guys were friends since sixth grade. How was your first impression of each other?" and Gaeko replied, "Choiza was big and looked old.  There were 70 people in one class, he was tall enough to be somewhere between 45 to 50.  He looked old, but I think he looks younger these days.  He's like Benjamin Button."

When the DJ commented, "It must have been nice listening to music and being able to bond over that when you were young."  The duo replied, "We would buy different CDs and share them with each other."

Gaeko complained, "When I listened to the CD, the other side was definitely shiny like a mirror, but after lending it to Choiza and getting it back, there were lots of scratches to the point you could not look at your face.  It was something I held dear, but when listening to it [after lending it to Choiza], the breaks [in the song due to the scratches] made me angry."

SEE ALSO: Dynamic Duo announces first European tour since their debut

Choiza was asked, "How was Gaeko during his younger days?" Choiza replied, "He had a lot of friends.  At the time, I was introverted, but Gaeko moved around a lot with groups of friends.  He also danced extremely well.  During rests, he would dance in front of friends, talk, and the like."

Gaeko elaborated, "I was like that in elementary school, but after, I was lonely.  I did not study much, either."