I have a few stories about wayward pilots. In fact my best mate was one. He bought a twin to do his PPL and I eventually got the phone call from his instructor: "I'm fed up with him telling me what we're going to do every lesson. As you are his best mate, who also flies, I just want you to know we're recommending he stop flying altogether, in fact we have decided not to accept any more bookings. He's a natural but he can't be told anything and is completely fearless".
They were right - he had no time for pre-flights and treated the aeroplane like his car - get in and start up. A great guy too, who loved his toys (and still does). He took it remarkably well and I still got the phone calls to join his family on flying trips, which is where I wrote up many of my twin hours.