It's more like we live in an age where we can observe the remnants of big-bang. And that age existed before humanity (we're just some 150.000 years old, a mere nothing on a cosmological scale) and will still exist after humanity.
I mean, we're talking tens of billions of years into the future here. Even if our particular branch of life do exist then, it will be more different from us than we are from, oh I don't know, frogs? If I'm allowed to speculate, I'm guessing humanity will exist until the end of the universe, but not in biological form. It's so, hmmm, inefficient
So this might be a time to observe these facts of nature, but it is a pretty large window of opportunity.