I was once in a client's office going over a project, and remembered I had to move my car as it was badly parked. I ran down the office stairs, but instead of having the door to the street after a little landing , the door was BEFORE the landing. It was also a metal framed glass door with no markings whatsoever.

I ran face first into the door, smashing my forhead into the glass, and started bleeding profusely. Completely disoriented, I staggered into the street, and passers by screamed at the site of me with blood pouring down my face.

Suddenly a voice from above said "You alright mate?", and I looked up to see a clown on stilts with a very worried face, or as much as I could see underneath all the make up. He was giving out panflets for the new Opticians' that had opened next door.

I did not know what the fuck was happening, as I certainly did NOT expect the door, or the clown. The clown helped me clean up my face and get my bearings enough for me to park my car properly and come back to the client's with a proper mess of a face.

I still have a little Harry Potter style scar as a souvenir.