It means that life is short, so why don't you try something you're afraid to do now? This quote comes from a golden translation of an American talk show I'll try anything once (life is short, why not try it once).
Life is bitterly short (rén shēng kǔ duǎn), which means bitter that life is too short, is an inverted sentence; bitter is not an adjective here. As with go day bitter much, it does not mean that there were many bitter days in the past time, but bitter that life is too short. Time was not properly appreciated.
Sometimes it also means "life is bitter and short", where bitter is an adjective.
Buddhist view:
In Buddhism, the view that the nature of the world is suffering, because everything in the world is impermanent and constantly changing, and gain will inevitably lead to the loss of the results of suffering. The world's laws are all relative, with birth and death, and gathering and dispersing.
Su Shi had left words to do the unprecedented melancholy: "people have sadness and happiness, the moon has a roundness". The night of the wedding ceremony will be replaced by the separation of life and death with the passage of time. Therefore, to look down on this chaotic material world, should strive to pursue the inner nature of the original.