do you ever?

Do you ever feel like you know someone but then they do or say something that makes you look at them like a complete stranger? It is simply the worst feeling. It almost makes you want to start crying. Changing the way you've viewed a person for so long is hard. Because you've based the way you've treated them on how you think you know them. And in a split second, that can all change.
But then you think, there is no room for you to judge a person. And it gets confusing, and you have a fight with yourself in your head. And that outcome is...I miss you. I miss the person you were. But, this person is different, I need time to get used to it. But I do love you. I always have and always will. Let's be friends. But this is hard...