Trump lies, knows he lies and doesn't give a fuck about it. He knows that the people who believe him already live in an alternate reality. If he claimed there's an ongoing attack from Moon inhabitants, the Trumpists would unload their AR-15 shooting at the Moon.
What matters to him is being acclaimed by some, even if it means being considered idiotic and unreliable by most. That guy is like a 5-year old in need of constant attention, he will do anything to get the spotlight.
If newspapers were stopping talking about him for a week, he would declare war to China just to be in the headlines again.