When Joe Biden says “not a joke” and “this isn’t hyperbole”, it means he’s currently engaging in a lie.
I heard that when he plays poker and is bluffing he always says, “Not a bluff, no joke.” He still takes Kamala for a good haul. It helps that Dr. Jill makes sure he’s holding the cards with the pictures facing him.
If that would be Biden’s Best decision he ever made as president, then I have to wonder what he would say was his Worst decision.