The Entire Universe is Just Part of an Incredibly Large and Incomprehensible Being
...and we can never explore it like science fiction tells us we'll be able to do. We are tiny, fragile things living on an infinitesimally small speck of dust floating in an endless sea of death. Most of the universe is made up of stuff that is completely incompatible for human life, and even spacetime itself is working against us should we want to travel freely within it.
To take it a step further, do you imagine that the individual cells in your body are aware they are part of "you", a living, breathing, sentient creature? Do you imagine it could build some sort of vehicle to fly outside of you to "explore"? And even if it could, do you think it would have any kind of perception as to what everything it's seeing actually is?
The idea is absurd. No matter how hard it tried, that cell would never be able to comprehend the things that make up our world. It just wasn't made to exist in it, and no amount of scientific advancement on its part would ever change that.
As much as I love the idea of exploring the millions of points of light in the sky, or understanding our actual place in the universe, or figuring out exactly what the universe IS, I simply don't think it would ever be possible...
...unless we evolve into something greater than we are now.