Every year, in the midst of dreamy spring weather, the cherry blossoms bloom in magnificent splendor. People flock out to enjoy the view and the weather and to socialize beneath the flowerly trees drinking copious amounts of sake. This practice has been going on for at least a millinium and few people actually ask the philosophical connotations this unofficial festivity implies.
Yet everyone knows. If you have lived in Japan all your life, you pick up hints here and there and become subliminally aware of the vicious undertones. Soldiers in Japan wear stylized cherry blossoms on their shoulders instead of stars. Reactionaries consider the cherry blossom their most cherished symbol along with the Rising Sun and the Imperial Crest. Almost every war song has some reference to cherry blossoms. Even avowed pacifists and Buddhist monks think of cherry blossoms as symbols of "transience", a polite way of saying "death". But there is more to it than that. It is not just the inevitable nature of "transience" that the cherry blossoms signify. It is the beauty of its brievity.
Cherry blossoms bloom and shed in a blizzard of petals in a matter of days. So which is the more beautiful, the blooming or the shedding? Is our appreciation of the cherry blossoms enhanced because it is so fleeting? Would we appreciate it more had it been more lasting? Or do we cherish it because it disappears so quickly?
The Romans said "Bibamus, moriendum est" ("Drink, for we shall die") and that is the spirit of hanami. Beauty is fleeting. Life is short. Respite from the sundry grindstone is brief. And so we drink. Just so we can experience the sadness of temporary glory slipping away. But since the point of the celebration is to forget the misery, nobody ever mentions why they are drinking.
Hanami is the celebration of the fleeting nature of life. It is a reminder that life, and particulary youth, is short. We drink to the passing of another glorious season in hopes that our lives will be just as glorious. It is a toast to the short-lived excellence saying "May we one day shed away as gracefully as the cherry blossoms".