All narcissists have the urge to do what they desire now. As a White House staffer, you can help your president develop patience and learn some basics about time and how it works.
If your president asks to use his smartphone to send an angry tweet to General Motors while sitting with the prime minister of Japan, calmly explain that he must wait until the meeting is over. Don’t ask him to be patient for very long, though.
Asking more than he is capable of giving can backfire. If he shows any ability to wait and delay his desire, use a gold Sharpie to add a star to his reward chart.