He got the whole thing mixed up.
He was trying to quote Mandy Patinkin's character, Inigo Montoya, after listening (too many times) to Vizzini's (Wallace Shawn) cry of, "Inconceivable!" Inigo looked at Vizzini & stated, “I do not think that word means what you think it means.”
Definitely a great move, "The Princess Bride." Lots of quotable lines, gut for now, let's just say of Musk that one usually must say, when having an intelligent discussion,."I'll explain & I'll use small words so that you'll be sure to understand, you warthog faced buffoon."