A lot of bummer answers here and they are many feelings I have had, but now I am old, and I look at it like this. I once didn’t exist. One day, I will again not exist and I’ll never exist again. In the meantime, I get a very brief glimpse to open my eyes and see the universe. In it is a lot of things. Among them love, mac and cheese, peanut butter, sex, and dancing. A hearty laugh and a warm hug is worth all the pain it comes with.
There are theories of an endless universe where the Big Bang is followed by a Big Crunch, and that just keeps happening for infinity. And through the magic of infinity, every possible arrangement of atoms will eventually exist, and even each instance will exist an infinite number of times. Some put these events in parallel, others in serial.
But when I get all sad about not existing, it’s nice to think that in a time inconceivably far into the future, I’ll be here again, and again, and again.
Just for the sake of fun conversation, unfortunately the Big Crunch models have fallen out of favor since we discovered the universal expansion is accelerating indefinitely. So… this may be it. Or it may not, but oh well. Eat some marshmallows and dance a jig.
Well, there’s also the many worlds theory.
But also there was something about the universe being twice as old as we thought. I’m no astrophysicist, but it seems like it’s far from being settled science.