They tell us that the universe began with a rapid expansion about 14 billion years ago. That carbon didn't become widely available till about 8 billion years ago. Our own solar system formed about 4 billion years ago. It really came as a shock to many that the universe as we know it had a beginning. Now it appears that it will also have an end. Although the parts of it are flying apart faster and faster, the individual elements will get wider and wider apart until the last star burns out and all falls into darkness and cold. I don't know why I would worry about it. My life will end within another 50 or so orbits around the sun. Maybe a lot fewer.
When I was reading some quotes from Carl Sagan, I ran across a photo he had made from Voyager looking back at a tiny speck in a dark sky. It was earth from 14 billion miles away. He commented on how every idea, person, dream, anything experienced by humankind had occurred on that tiny speck of dust. It was humbling. In the midst of all that nothingness, our significance fades. In the great distances between the stars, limited to the speed of light, it would take eternity to travel in it. And the trip would be excruciating boredom. Someone once said the universe was made from nothing, and the nothing shows through. To live and travel in that empty place....eternal life just wouldn't be all it cracked up to.
Sometimes when I speculate on the meaning of my life, I can't begin to comprehend the question. Other times it seems as simple as finding some joy, some comfort, and some pleasure in the day, then settling down for a long sleep. The thought that some particles of my being will ultimately be scattered amongst the incalculable distances of the Cosmos gives me solace. There will be no monument to my life in any of that, but something of me will endure.