There was a hilarious short story by Harry Turtledove called "The Road Not Taken". It dealt with the FTL armada of an alien empire who arrives in our system and after detecting no signs of hyperdrive or gravity manipulation realize the Earth is ripe for conquest.
The story becomes absurd when the aliens land and engage the national guard with matchlock rifles and black powder bombs. The national guard responds with automatic weapons, tanks, missles and jets.
As it turns out gravity manipulation and hyperdrive doesn't require more than a 16th century level of technology to create, (go FTL with this one simple trick!). The technology didn't have any other applications or lead to any other scientific breakthroughs. So most species who reached that level stopped doing science and ended up exploring or in galactic conquest.
Humans on the other hand somehow just missed the technology and in doing so took "the road not taken". The road where we learned electronics, medicine, agriculture, computers, and nuclear weapons. When the captured alien survivors realize just how far ahead of them we are and that they just gave us the keys to the galaxy they shit themselves.