The concept of mono no aware suggests an awareness of the impermanent nature of everything. Generally translated as "the pathos of things," this awareness intensifies the appreciation of beauty, and evokes a poignant acceptance at its passing. Unlike Western ideals of beauty - primarily based on a external perfection - in Japanese culture, beauty seems to be embraced in a more subjective fashion; as an experience of the heart and soul, not merely the fives senses.
With mono no aware, the ground strewn with fallen sakura petals is just as beautiful - or perhaps more so - than the fresh young blossoms clinging to the trees. And, because everything is impermanent, getting attached to things can lead us to suffering (at least according to the Buddha, who, I think, nails it here). It's not just a "stop and smell the roses" philosophy, but a "stop and smell the roses and sadly rejoice in their inevitable passing as a proof of this truth" philosophy.
But, as I consider this Sunday, and the previous years' festivals we attended, I can't help but think of how things pass so quickly when the kids are still kids. Even though this was only the third Sakura Sunday we've attended, I can see how they are all changing, growing older (though, thankfully, not growing up too fast). Soon enough I'll be completely extraneous.
So, for now I'm going with mono no aware and reminding myself to appreciate the fleeting beauty in all things - the cherry blossoms, the seasons, and my teenage daughter's need for her mother.