Question 26 of 365; Do we really know the people we think we know?

Does this sound crazy? We grow up with people our entire lives and we spend years of friendships with people getting to know them. But do we really know the people we think we know? We can predict what we think people will do based on the character they present us but sometimes they do the total opposite. We say people wouldn't do something but they end up doing it. To be honest, I don't think we even fully know who we are let alone other people. People change, we change, I change. Are the manifestation of people illusions too? Is life an illusion? What is real and what isn't? I know that me typing this is real but are the ideas of my friends and family real? I think they are, but are they really?