I suspect there's a good chance that Trump believes pretty much anything he's told by whichever sycophant had his ear last, so long as it's in service to his ego. He should say stupid crap because it'll earn him money, great! Trump likes money! He should say stupid crap because it'll hurt people he doesn't like? Awesome! Trump likes hurting people. Particularly certain ... sorts of people. He should say stupid crap because it'll get him back the prize that was taken from him? Fabulous! I'm not sure he ever truly wanted to be president or particularly enjoyed the job. That's not important. The important thing is that he had something and then someone else took it.