Someday stars will wind down or blow up. Someday death will cover us all like the water of a lake and perhaps nothing will ever come to the surface to show that we were ever there. But we WERE there, and during the time we lived, we were alive. That's the truth - what is, what was, what will be - not what could be, what should have been, what never can be.
The passage reflects on the inevitable end that comes to all living things, suggesting that eventually, even the brightest stars will dim or explode, and death will envelop humanity like a vast lake. This evokes a sense of impermanence and the fleeting nature of existence. It emphasizes that despite the eventual silence, there was a time when we truly lived and experienced life fully.