This story is attributed to Bill Purcell, though we have not been able to confirm the authorship.

An old maxim says that when it hits the fan, it will not be evenly distributed. Imagine with me one place where it splattered against a wall and dried before it could be cleaned up.

Now, there was this chap who had been blind most of his life and who was very competent at reading the raised punch-marked notation called the Braille system. One day he went into the room containing the wall and, as it happened, tried to decipher the writing on the wall. With a look of puzzlement on his face he asked, “Who wrote this crap?”