What's even crazier is that those civilizations could have built and advanced for a 100 million years and we would never know about it because they are so far away. The light from Canis Major, our closest galactic neighbor, is older than our civilization (25,000 years). The average distance between galaxies is 1 million light years. For all we know, there have been billions of civilizations that have lasted longer than the lifetime of our solar system and we haven't even seen the light from them yet.

The universe is huge!