Osu!
The sense of self-sacrifice has always been deeply rooted in being of the Japanese people. Since the 6Th century at least they have been fed on the Buddhist idea of the impermanence of all things. In particular the Samurai and Bushi were aware of this fact, due to the perilous nature of their calling, and they likened life to the cherry blossom: so fragile, so easily blown away by the wind. They did not put the same value on life as the peoples of the West. In effect, for them life had no meaning except in death - but not just any form of death; not a useless and pointless death, an involuntary or unexpected death. Death finds its meaning in sacrifice, which then gives its full significance to the act of living. And the Samurai who, with a light heart resulting from "Kokoro", sacrifices his existence in the service of his lord or for the sake of a cause, had the feeling that by dying he created life. This is why the notion of sacrifice was always so important in Japan. The idea of death was a course present in Martial Arts to the same extent as the idea of life. Ideally my friends, its presence never left the warrior's awareness for an instant, for in the end he was truly living with death itself.
Louis Frederic
My friends in the Book Zen Mind, Beginner's Mind we have to study this, we are constantly in transience and once we accept the understanding how quickly we can pass into and out of existence as the Samurai the more we understand Mizu No Kokoro.