http://www.politico.com/magazine/story/2016/08/7-reasons-why-trump-would-hate-being-president-214192
I don't think he really knows what the job entails. He will die of boredom because things move very slowly in the WH. He can't just up and fire anyone. He can't just up and fly his jet to Mira Lago in FL to de-stress any time he feels like it. He will have to attend to all the mundane things President's do every day.
According to the article he'll be investigated to death. Everything! Yeah, he's going to love that. (Hillary is already used to it.)
He'll need to show empathy often in many situations, something he doesn't possess.
Remember the saying, "be careful what you wish for" Trump.
Of course he can fire people. Cabinet members serve at the pleasure of the President.
