In the beginning, Pharaoh could handle the plagues’ setbacks, but when things became unbearable, G-d hardened Pharaoh’s heart so that he would have free choice. G-d wanted things to be fair. He wanted Pharaoh to be able to withstand all the plagues’ political pressure. G-d wanted Pharaoh’s choice to be untainted by the climate of catastrophe, so He hardened Pharaoh’s heart against the pressure. G-d enabled Pharaoh to continue to choose according to his true desire, without being swayed by external factors. Therefore, Pharaoh adamantly persisted in his refusal to free the Jewish people.

In so doing, G-d also was also able to mete out punishment on the Egyptians for their insatiable cruelty, as well as perform wonders and miracles on behalf of the Jewish people. 
 
But if you still want to know if Pharaoh was nuts, you’ll have to go to askfreud.com.