Genesis 47:19 Wherefore shall we die before thine eyes, both we and our land? buy us and our land for bread, and we and our land will be servants unto Pharaoh: and give us seed, that we may live, and not die, that the land be not desolate.
So yes, Rameses became an extremely wealthy man who accumulated extensive real estate through the providence of God, so when he says “I know not The Lord” he was just telling a flat out, blatant lie. It was a deliberate, conscious decision that he made to totally reject the undeniable evidences of God’s kindness toward himself and the nation as a whole. At that time, as far as advancement in knowledge, sciences, art, education, and military prowess, Egypt had become the equivalent of the United States, in our day.
And no doubt, Egypt was the bread basket of the world under the wise leadership of Joseph, who was led by God Himself. But, as was stated before, Rameses 2 was a fool, for not only denying the existence of God, but also for accepting praise and worship which belongs to God alone. All pharaohs considered themselves the sons of Ra, which they embraced in their titulary. Carrying the title “son of Osiris” he was worshipped as a god, and to his poor subjects he was the zenith of both religious and political leadership.
But what is particularly troubling is that the ordinary citizens of his realm did not have a problem in addressing him, and worshipping him as the “good god”. It's one thing for the leader of any nation to think of himself as a god, but whenever the citizens begin to worship him as such, they will enter into the twilight zone of spiritual darkness, which in most cases ends in national destruction.
Genesis 47:20 And Joseph bought all the land of Egypt for Pharaoh; for the Egyptians sold every man his field, because the famine prevailed over them: so, the land became Pharaoh's.
May The Lord add His blessing to the study of His word. God bless!