mono no aware

• mono - thing, or person.
• no - possessive, marks that what precedes it is the owner of what follows it. or, that the following is a function of what precedes it.
• a(wu) - to meet, or gather, or match.
• ~are - marker of passivity for verbs, and in this form, a nominalizer

• "That's the way the cookie crumbles." ~ English
• "C'est la vie." ~ French
• "That's baseball" ~ Walter Matthau
• "So it goes" (thanks Ichiro2k3!)

IanOji's writeup is not entirely accurate.

The concept of mono no aware has been translated by the scholars of japanese literature as "exclamation of sympathy or distress" (Arthur Waley), "the pity of things" (Ivan Morris), and "the sad transience of things" (Stephen Shaw), among others. The concept of the transience of the world is a fundamental principle of Buddhism, which was gaining traction in the Heian period (from which the concept of mono no aware originates)

So where does the concept of "sadness" or "pity" come from? Mono no aware, in japanese, is written 物の哀れ. Using the kanji "哀", we see that the reading for "aware" (roughly pronounced ah-wa-rey) is not the verb 'au' but an adjectival noun meaning "helplessness, pathos, pity, sorrow, compassion".

While the literal meaning of the phrase is not difficult to understand, the phrase's "untranslatable" nature is a result of the cultural nuances it evokes.

Norinaga most famously applied his theory of mono no aware to the Tale of Genji, and indeed many textbooks now erroneously date the concept from that time, but Norinaga believed that the concept applied to all Japanese literature all the way back to the Kojiki, boldly making the blanket statement that, "all Japanese poetry is composed through knowledge of mono no aware."

Norinaga believed that the Japanese as a race had a singular capacity to experience the objective world in a direct fashion, to profoundly understand the objects and the natural world around them without having to resort to the mediation of language. Moreover, not only could the Japanese uniquely understand the world in this direct way, but their language was also uniquely suited to express this direct connection to the world.

On an interesting side note, although mono no aware is often also associated with cherry blossom viewing, there is no evidence that cherry trees were more important than any other trees in the Heian Era, and indeed, the Yoshino cherry tree that is so ubiquitous in modern Japan was not even invented by horticulturalists until the 1820s, more than 20 years after Norinaga's death. Before that, Japanese cherry trees could only be found high in the mountains, didn't have many blossoms, and viewing them required a special trip that only the wealthy could afford.