"You think you know someone. You think you know what they're about, what they feel, how they think. And then in one action, one moment, you think "they've changed". But then the realization sinks in. It's not the person who's changed, it's your perception of them that's changed. They are the same person they were, it's how you view them that's changed. And it makes you think... did you ever really know them at all, or were they merely the creation of what you wanted them to be?"
-Henry David Thoreau
(thank you, jenka)