Overinflated sense of self importance
Back in my helpdesk days, I had an "important" customer with a completely F'd laptop. We went above and beyond for him, got a replacement laptop spun up in record time and had a priority courier pick it up to drive straight to the customer for same day delivery. When I kindly informed him that a new laptop would be with him in just a few hours, he was furious! "What am I supposed to do for the next few hours!? Do you know who I am!? What are you going to do to make this right!?" After much pointless discussion I ended up saying to him something to the effect of "I don't know what you expect me to do, it takes time for an object to travel through physical space."
He asked to speak to my manager.