"Aish, lame boy, still hasn't grown out of the concept of imaginary friends."
Kim Seokjin has never had any friends. Not a single one. He's used to being a loner, going places by himself and all. Although, to be completely frank, he's never had any REAL friends. As in, no real people that aren't just figments of his imagination. So, for the first 18 years of his life, he was accompanied by 5 imaginary friends, by the names of Jimin, Namjoon, Jungkook, Hoseok, and Yoongi. All simulations of real people invented by his mind, tailored to fit his ideal group of friends, with cool personalities, senses of fashion, and eccentric and creative hair styles and colors. They helped him escape reality.
It is also said that the brain is not capable of creating a face. Seokjin knew this fact, yet ignored it, believing that he was the exception. But when it comes to science, there are no exceptions, no odd ones out.
So, when he went off to college, let us just say he was very surprised to see the face of the person he was rooming with.