Why do all things come to an end?
People often pose this question just about good things, because no one wants them to end. Yet they do and it's not just those - all things good, bad, ugly, sublime and humdrum come to an end. This presently disastrous looking time of pandemic, death and falling economies will also come to an end just as surely as the most sublime love or times of the greatest developments.
I've heard of the so called Chinese proverb "this, too, shall pass". Well, Chinese or not, it's perfectly true. Those who are scientifically inclined would know of the unidirectional arrow of time, also called arrow of entropy. Since time moves one way, nothing lasts. Individual lives are measured in days to decades depending on the species while the lives of cosmic objects such as stars and planets are measured in billions of years.
Things are cyclic, though. The idea is conveyed in this verse taken from a highly philosophic Hindu scripture called the bhāgawad gīta (divine song).
वासांसि जीर्णानि यथा विहाय
नवानि गृह्णाति नरोऽपराणि ।
तथा शरीराणि विहाय जीर्णा-
न्यन्यानि संयाति नवानि देही ।।
Transliteration and translation:
vasāmsi jīrnāni yathā vihāya
(when clothes get old and worn)
navāni grhnāti naroparāni
(people take on new clothes)
tathā sharīrāni vihāya jīrnā
(and when bodies get old and worn)
nyanyāni sanyāti navāni dehī
(souls take on new bodies)
I'm not advocating the theory of rebirths, but rather I'm referring to the idea of cyclicity in nature. Even when stars die and explode in supernovae, they trigger the birth of a new generation of stars.
If you are feeling down, this, too, shall pass. And it will be replaced by something new. So it has always been.