Because if this fact doesn’t hold true, then generally no one on earth is Beautiful.
Come to think of it, It’s our imperfections and not our perfections that differentiate each of us. If everyone was perfect, if everyone was flawless, then all of us would just be similar homogeneous photocopies of one another. Meeting you would be meeting a mirror reflection of yourself, of myself, or the person sitting across you on the subway.
So embrace the fact that you are not perfect. You are a unique you and a (as cliche as it might sound), one in a million.