Watching documentaries about universe always makes me sentimental. There a lot of thoughts slide across my head, here are just some of these.
Now we know, the sun is going to swallow us all in about 5billion years, one way or another, our solar system is doomed. But that length of time is so long that it doesn't mean anything when we focus on the Individual, like you and me. We only live 80years averagely, 120years at most, so we don't need to bother about what would happen in 5billion years. Maybe we would invent some technology to get us out of the apocalypse. Maybe we would kill each other in the last few decades.
Anthropic Principle tells us everything has to be the way it is, or we can not exist at all, not to mention to explore the way how universe works. We should thank how lucky we are that everything is the way it is. But we don't in real life, maybe we don't even realize this fact.
There are almost infinite stars in the galaxy, there are almost infinite galaxies in the universe. It's way out of my imagination to portray the whole known universe. Apparently I can't live to that day when we make travel through galaxies possible and a feeling of sadness surges up.