Brian GordonYes because he's a narcissistic psychopath. It's what they do to show dominance.
"By resolutely asserting unbelievable falsehoods, Trump is expressing contempt. He is deriding the enterprise of journalism, in effect forcing reporters to write stories about his incredible statements, thereby indirectly controlling the news cycle.
"It seems to me that his purpose is not to convince anyone, but rather to declare to the press, and perhaps also to his opposition, “You cannot stop me.”