By now you know what the Fermi Paradox is. If the universe is full of extraterrestrial life (and most scientists think it is, with varying definitions of "full"), then why haven't we found any aliens yet? One hypothesis says we're basically exhibits in an intergalactic zoo. When was the last time you wrote a letter to the monkey house's bonobos?
Another theory says we're just too stupid for aliens to bother. Thanks for the vote of confidence, Neil.
But here's a novel idea: what if aliens are out there, but "hibernating" until the universe is more to their liking? Perhaps the truth is out there, but it's taking a nap.