In this quotation, a view of beauty is presented which tallies with that seen across literature for generations. Keats discusses beauty as "truth" while Shakespeare, in his sonnet cycle, repeatedly returns to the idea that physical beauty, like the beauty of summer flowers, is especially to be cherished because its lifetime is short. Eventually, all things that are beautiful will come to an end, and we prize beauty more because we know that it cannot last forever.

This idea is repeated here in the quotation you have selected. The speaker suggests that beauty exists because it is "ephemeral." Because we know that the beautiful thing, be it a person or a flower or something else, will eventually fade and degrade, we prize its beauty more, knowing that we will not be able to enjoy it forever. The speaker suggests, therefore, that we should translate this means of experiencing joy into our lives as a whole. If we are able to make ourselves constantly aware that the life we live is ephemeral and will not last forever, we will be able to enjoy ourselves more. By being constantly conscious that death will put an end eventually to everything that we love, we will be able to live more in the moment, recognizing that the end of life is, inevitably, death.