At 2 billion years older than Earth, I can't begin to imagine what kinds of things could possibly be living on this planet. Given, of course, that it's got the right ingredients for life to arise. What if it's suffered huge extinctions recently? What if there's a domineering species out to conquer the planet just like humans? What if there's a society there more sophisticated than us? It's a very exciting discovery.
So we could be in ZOO experiment. Other civilizations want to see if we are capable of evolving and joining them so they make sure we are not disturbed by other life out there because if we discover intelligent life, we will freak out. We might start fighting for our survival and it could affect our evolution to higher species.
We could also be a part of some computer simulation (with enough power you can create rules with particles and simulate the universe). Maybe somebody is trying to answer this question: If you create a big enough simulation, will be the simulation able to figure out it, it is being simulated?
Or maybe everything that we see is true but it is just impossible to overcome some physical limitations. We assume there are no limits and everything is possible and one day we will master it. But what if communicating and traveling through universe is nearly impossible? Maybe there are limits that we don't know about yet.
Maybe every civilization reaches point where they know the answer to everything and they don't see a reason to live anymore or they leave the universe and move somewhere else.
My point is that we assume something that will eventually turn out false and everyone will be surprised by the truth.