Actually I think only the lower-class people could be fooled into believing the Pharaoh is a God. The ones who lived with him in the palace could see him being sick, angry, sad, whatever and probably they realized he's only human.
Meritaton, what about the stories of the God's where they get angry, sad, worried, tricked by other Gods? What about the story of Horus when he was bit by a scorpine got so sick he almost died. What about Sekhmet's getting so drunk she forgot to kill more Egyptians. Or Re's anger so great that he ordered Sekhmet to kill the Egyptians? Or Isis tricking Re into to telling her his secret name? If the God's could feel as man in similar situtations why couldn't Pharaoh?
I believe even Pharaoh himself believed himself to be a God. I believe that his palace nobles, priests, and servants believed it too.