I don't think that Trump actually enjoys being President. Of course, he likes the *idea* of being president - the adulation, the power, the attention and so on. However, I strongly suspect that he doesn't like the day-to-day work.Y'alls hero, being the sulking little bitch that he is.
What Trump likes is the opportunity to thrust himself into the public eye, to be the centre of attention. This is why he enjoys political rallies so much. I'm sure that he'd enjoy being president much more if it was basically a figurehead, monarchical position.