Trump's the only person I've seen with the ability to gaslight himself
At first he starts saying he was robbed because he's mad that he lost, and then soon you can tell he really believes it and every time he repeats it the claims grow and grow (now he's saying that he not just won, but won in a "landslide").
Actually you could see him get high on his own supply mid-sentence in his election night non-concession speech when he said "We were getting ready to win this election. Frankly, we did win this election!"