We think we know somebody.
But remember - there are MILLIONS and MILLIONS of thoughts that go through this persons head to which we are not privy. People only share what they choose to share and very selectively. And beneath all of those thoughts there are the person's feelings. And beneath those feelings is their soul about which we know nothing.
So all we have is the way they look, some behavioral patterns and some things they say. A very minor mirror into the real person....
There are a lot of conclusions that this insight should lead one toward.
I will let you reach them yourself.
One more nibble of food for thought: How much do we truly know OURSELVES???