An invisible man is here to see you
Nurse: Doctor, there is an invisible man in your waiting room.

Doctor: Tell him I can't see him now. Next.

As a sergeant in a parachute regiment...
As a sergeant in a parachute regiment I took part in serveral night time excersises. Once, I was seated next to a Lieutenant fresh from Jump School. He was quiet sad looked a bit pale so I struck up a conversation."Scared, Lieutenant?", I asked.He replied, "No, just a bit apperhensive."I asked, "What's the diffrence??"He replied, "That means I'm scared with a university education."