So I have heard people sometimes say the reason for no aliens is that complex life requires so many coincidences it is just incredibly unlikely to indecently arise anywhere else in the universe. I think it is a bit arrogant to assume all life has to mimic life found here on Earth, so forgetting the goldilocks zone for a minute, you still need life to emerge from nothing over the course of billions of years. Then you need complex life to emerge from that, and eventually civilization. But you know what else you need?
Extinction.
No extinction means no fossil fuels means no industrial revolution means no spacefaring. If it wasn't for the dinosaurs, we would have nothing. Makes you wonder what we're here for.
I conclude that any advanced alien lifeform that gets to this stage will have to use a source of power not used so much on Earth. Hydro and Thermal seem unlikely, it's less portable and requires huge facilities, so it will probably have to something else. I imagine rivers of liquid gas, a space-faring civilization built upon lakes made up entirely of methane.
Edit:
It has been brought to my attention that fossil fuels are not in fact made up of ancient dead dinosaurs, and even if they were, we wouldn't need a meteor to make this happen. I just like Dinos 
This, plus the time it would take for signals to travel space at the speed of light, not even mentioning matter at sublight speed, makes it just implausible that we'll ever encounter another civilization (assuming there are some out there)
Plus, I remember reading that the constant expansion of the universe makes it another big factor as we are ever drifting away from most of the rest of the universe, but I'm not sure
You are correct, but the expansion of the universe is relative to intergalactic space, not interstellar. Our galaxy isn't flying apart, so it will be explorable with currently theorized faster than light speed drive systems. There's more than enough to explore in our galaxy as it is, so it will have to do when and if we ever develop an FTL drive. But traveling to another galaxy is an entirely different feet because of the expansion of the universe. You may wonder why, when it is just a distance that needs to be covered, all you should need is enough fuel and supplies... But you would also need to accelerate to many magnitudes of the speed of light in order to "catch" the galaxy you want to travel to. This is because galaxies are accelerating exponentially away from each other. An easy way to visualize it is to remember that the universe is expanding out from a central point - so take a balloon and draw two dots on it, then begin to inflate; after one breath they spread apart, after the second breath they've spread appart at a faster rate, and after the next the rate of spread continues to increase and so on. The points are spreading away from the center at the same rate, but the distance from each other is ever increasing. Therefore, their will be a day where we can no longer see any other galaxies again, because the speed of the spread will far exceed the speed of light and continue to increase for all eternity (we presume).
Except for the Andromeda galaxy, that one's headed right for us and the two are going to collide in a few billion years... Which will probably pose a major threat to all life and indeed earth itself... Maybe we should start planning to try to get to another galaxy. ๐ค