im starting to think that intelligent civilizations are REALLY rare, as in impossible to find. think about it, out of all the literally millions of species on earth, only one has reached the ability to do some minor space travel... and it was a huuuuge fluke. without humans, the Earth would have likely existed its 8-10 billion or so lifespan without any intelligent civilizations. so it could very well be that for every one out of a billion planets there will develop life, and out of those only one in a billion develops life intelligent enough to explore space.. making us and other potential civilizations a total needle in a haystack. (a drastic understatement of course).
i imagine our galaxy and most other galaxies having quite many planets and moons with single-celled life, but much fewer planets with multicellular life, and perhaps only 1 planet (or moon) with a space-exploring life form, IF the galaxy is lucky :/
or for an even more bleak outlook, consider this: maybe our sense of realitys scale is totally off, maybe one universe is just a tiny speck in a bigger multiverse, and maybe that multiverse is just a tiny speck in another bigger structure and so on and so on... making galaxies and even universes incredibly small parts of the big whole, meaninglessly small even.. which could mean that life is so inconceivably rare (from our perspective) and so sparsely spread throughout the whole of reality that maybe civilizations or any life at all only sprung up once in every universe... making it absolutely impossible for any advanced civilizations to ever get in touch with each other in any way, even if they were relatively common in the multi-multi-multiverse.
hopefully i am wrong. the truth is that we have not even really started to explore other worlds yet (despite the numerous exoplanet findings), we dont have single clue about anything really. we can only speculate and pull stuff out of our asses like i just did above.