We love the cherry blossoms in spring because of their short existence on earth. If these flowery manifestations of the power of life stayed for months, our enthusiasms would be greatly diminished.
When you think about it, everything in the universe is in permanent motion. A tiny stone on your desk, which, after being forced out of the earth and transported and gradually destroyed and frictioned by the workings of water, seems finally to be at rest. However, inside the cool and still image of the stone surface, electrons are swirling around the nucleus in an eternal zitterbewegung, the positrons and neutrons and the quarks that make up these particles are in constant motion, even being destroyed and created from nothing in the poignant void of space-time.
Life is based on the perpetual motion of things, and therefore changes and deaths are inevitable. When we look up to the cherry blossoms, and witness their rapid demise from the prime of beauty, what is happening is nothing more than a result of the universal passage of time which affect life and non-life in the cosmos alike. The fact that we are affected and feel a sweet pain in our soul is ultimately an enigma, albeit so natural from the point of life's common senses, as nothing is changing in terms of the fundamental ways of things when it happens.