Actually, it's worse! The universe is going to get like insanely old, but even if you just take the 13.7 billion years that have already happened (and round that to 10 billion because fuck you, I'm allowed), if you live for a century, then you experience 1/100,000,000 - or one hundred millionth - of the show.
If we keep going with the show metaphor, most shows - plays, movies, concerts - are around three hours long, so let's go with that. 3*60*60 = 10,800 seconds, which we can again round to 10,000.
That means in all the time that's already happened, you get to see one ten thousandth of a second of the show.
But, okay, what if the greatest show is just a hominid thing? Hominids have been around for roughly four million years, and all the neat stuff like tool-making has been around for two million years and change. So, rounding that down to just one million years, if you live for a century, you'll have experienced one ten thousandth of the show. Or, in our three hour metaphor, you'll have experienced roughly one second.
You have just enough time to experience a burst of light and sound and the realization that Things Are Happening in that tiny, infinitesimal glimpse into the show, and then it's just... gone. And so are you, with all the knowledge and memory and love you've gained, because it may have been a second to the world, but it was everything to you. This is what haunts me late at night - that we all exist within a single breath of the world, and that no platitude can ever really make that stop being true.
But since I've dished out some existential dread, it's only fair for me to share the bit that gets me back up and moving, too.
It's NOT okay, and it COULD be better, and if I could have a thousand or ten thousand more years, I'd take them in a heartbeat. But the thing is, as it stands, we only get one second of the show, so we might as well make it count.
Do you know how much can happen in a second? Innumerable amounts of atoms collide, and lightning flashes in the sky, and you can say "I love you," if you say it really fast. We've had to make words for things that happen in a thousandth of a second, or a millionth, or a billionth, and we've even made it down to Planck time, which is so mind-bogglingly small that my brain breaks trying to imagine it.
And we're not alone, either. If a million people shout at the same time, even for just a second, it'll be audible for miles around. It destroys me inside that it's impossible to share everything we each experience with the rest of the world, but we can still share the bits that mean the most to us, and we can still pool our seconds to do something bigger than just ourselves. The most surefire way to make our second count is to not spend it entirely alone, and if that's all we get, then let's try to make it worth something.
And, hey, who knows? Maybe if we do a better job of working together, we'll be able to figure out how to get a bit more than just that one second someday.