I must share I once witnessed (which involved a big heavy computer room door,
so there is a tenuous link!!)

The operations shift leader had a habit, when his arms were full with printout
or tapes, to run at this door and appear to "nut" the door with his head, and
then feign he was slightly stunned. What he actually did was kick the door
with his foot, but his timing (and acting) was impeccable it was very
difficult to detect what he was really doing.

Anyway, one of his junior operators - a particularly gullible young man -
swallowed this performance hook, line, and sinker. Over several days he kept
pestering the Shift Leader to tell him how he could do it. The shift leader
warned  him that it was immensely dangerous and that it was only through
years of training in Tai Chi that he had been able to withstand the pain.

The Junior Operator continued pestering as to the actual mechanics of the
feat, so the Shift Leader told him that the secret was to run at the door as
fast as you can and at the last minute imagine your head was 2 inches the
other side of the door.

We were all sitting in the Computer Room one day when something crashed into
the door and it opened just a few inches and swung closed again. A low moan
came from the other side and when we opened the door this Junior Op was
sprawled on the floor with a very startled cleaner rushing towards him.

The cleaner told us the chap had rushed past her at a fair rate of knots and
ran head first into this huge door!!!

Cheers

Deri