"Life is", goes a saying in my native Finland, a country not known for using superfluous words. While this saying may take compactness a tad too far, it's a great way to say "things happen", mostly to stoically adapt, sometimes to justify actions taken in order to adapt. The brevity of the expression adds not just to the perceived wisdom, but also makes resistance futile. The expected and usual reaction is agreement; I have yet to experience a situation where somebody would counterargue that "life is not".