This is the fundamental problem when considering this question, isn't it? We are viewing the question from inside our own heads and experience. It's like asking a deaf-from-birth person what it is like to be deaf... I mean... what else do they have to compare it to? It's all they have ever known. If we look at the math of HUMANS traveling across the galaxy, then the distances and times become insurmountable. But what about beings with longer lifetimes? Or a predictable hard-coded evolutionary path, so you equip your ship with microbes, and eventually people step out at the other end of the trip. And how do those beings "connect" with the ones that sent them? And why were they sent to us?
This is one of those "fucking magnets how do they work" intellectual traps people get sucked into, though. There are only a couple different bases for life, and that's if you count silicon, which has a serious paucity of orbits for metabolic chemistry to utilize. Photosynthesis is likely to be green, yellow or red. We've evolved a truly thunderous array of biological shapes and adaptations, and in many cases nature has coalesced on the same solution a few different ways. Any intelligent life out there is unlikely to be standard Star Trek headbumps'n'makeup humans, but if you look at it, sentience is evolving on this planet through primates, cetaceans, corvids and mollusks. When we watch an octopus being clever, we go "whoa clever octopus" we don't go "my mind is blown at the task of conceiving of intelligence in a shape and form so different than mine." We're also at like 150 years of electricity and have long since defaulted to sending our tools ahead of us. A Mars lander looks nothing like us, it looks like the best solution we could come up with for a specific task. And every time we launch a probe we attach a little bit of us to it to push the dark back a little bit. I think it's reasonable to assume that any intelligent alien life we encounter will be mechanical, comprehensible and altruistic.
Yes, but it's not that hard to theorize outside that bony box. Bacteria can survive on ionizing radiation alone, I'd have no problem with a species that goes "3.6 Roentgen? Yum!" that traverses space in a fissionable self-sustaining arc. Gonna sleep on those questions, though.We are viewing the question from inside our own heads and experience.