Paul:  Trump has spend his like being "the boss."  He clearly considers himself "above" us mere mortals. 

 The Correspondents' Dinner has always been an opportunity for a President to "humanize" himself and exchange humor with his traditional adversaries on the press corp.  President Obama was extremely good at such exchanges; engaging in self-depricating humor and, clearly, enjoying himself and being "enjoyed" by the crowd. 

Judging by all his personal, business, entertainment and political history, Trump has neither the ability nor the desire to be "humanized" in any fashion.  As you say, he is who he is.  regards, Gary Crum