Not long ago, a young man was moving a sofa out of an apartment. The apartment in question was on the third floor. The building did not have an elevator. Before he had even descended the first flight of stairs, a bit of dilapidated concrete gave way. The young man fell through the step and caught his knee between the remaining portion of concrete and a rusty bar which supported the step. Fortunately for him, the sofa remained in place.
The young man suffered no more than a bruised knee and a scare. However, there are any number of worse ways this story could have ended. There are certain things a person takes for granted; for instance, that if one places one's foot upon a stair, the stair will normally hold his weight. It bears remembering that this is not always the case.
This is a song about all the things you ought to be afraid of.