That good parking places are always on the other side of the street. That a child can be exposed to the mumps for weeks without catching them but can catch them without exposure the day before the family goes on vacation. He was walking along a highway, dutifully obeying the rule of walking to the left facing traffic, when hit from behind by an Englishman who was hugging the left side of the road. Paul Dickson, a 39 year-old writer became interested in the phenomena of universal laws when he discovered that the size of the cut he inflicted upon himself while shaving was directly proportional to the importance of the event he was shaving for. If anything can go wrong, it will.
Nothing is ever as simple as it seems.
Everything takes longer than you expect. If there is a possibility of several things going wrong, the one that will go wrong first will be the one that will do the most damage. Left to themselves, all things go from bad to worse. If you play with something long enough, you will surely break it. If everything seems to be going well, you have obviously overlooked something.