I think he reacts the way he does because while he may have won the Electoral College vote, the actual vote count was much higher for Hillary Clinton and Trump just hasn't been able to process that.
She got almost 3 million more popular votes than The Donald John. Of course The Donald John's excuse for that was that according to him between 3-5 million people voted illegally. SIGH. Thank you for your reply Spunky! :)