Don't let the door hit you on the way out... 
Funny you said that. One did very recently on the way in.
Was at work, chucking stuff in the tech scrap bins. The heavy building security doors slammed shut with me on the other side, so I shouted .....through the gap in the door, "Carl, Carl the door shut".....silence...."Carl"...silence...so I tried to peak through the gap to see....BAM! Carl opened door....
Massive bruise on my eyebrow.....Still tender two weeks later. Getting older and wiser doesn't prevent moments of stupidity.