The idea of perception is unique, relative, subjective, and perhaps even ever-changing.
How we perceive ourselves and others is influenced slightly by everyone we meet, experiences we have, information we have learned, and perhaps even altered by current moods.
Certainly how one perceives oneself is different from how everyone around that person perceives them. Each person around them will have a different perspective, even if subjected to the same sets of interactions with that person. Because each one of them has a different outlook on life, and admires different qualities in the people around them. Of course mood will also affect the perception with somewhat of an enhancing affect on both ends of the spectrum between positive and negative.
Once the idea of perception is understood to be relative and easily affected, then with some effort it can consciously be changed to be more positive and uplifting, focusing more on the good we see in others and not dwelling on the rest. This is a real challenge sometimes, but with effort, it makes it easier to be happy and spread cheer to others around us more often. This is just one of many things I'm working toward lately.