Reflecting on my own life, I find that people are often mirrors on which I see my own reflection. This particular viewpoint, obviously, is related to the recent discovery of the mirror neurons. But the idea is not necessarily based on, and restricted by, the neurophysiological findings of today.
When I meet someone with whom I resonate, I discover and confirm what kind of person I am. The counterpart then becomes a magnifier of my own personal traits. When my counterpart finds pleasure in the same kind of things, I feel that my own dispositions are socially approved and consolidated.
On the other hand, I do sometimes meet people with polar views and sensitivities. Even when I present something valuable and dear to me, they would receive it with cool and sometimes even disdainful reactions. When I was young, I found myself unduly hurt by such a behavior. But gradually, I came to realize that such an occasion of miscommunication actually provided a significant opportunity to recognize my own self.
People are mirrors, when they are resonant, AND when they are dissonant. Every day, with the encounters with various kinds of people both young and old, passionate or quiet, I see millions of reflections of my own image. I recognize my own self. I am generally very grateful for these encounters, even when they hurt me.