not sure this mentions the concept of time, aliens could have died long ago or haven't evolved yet
Cool Guides
My personal pet theory is that we're just early to the party and don't know it yet.
Take the high school biology definition of life and throw it out, it’s shit. Broaden your thinking to include any sort of self replicating chemical system. The possibility space is so vast that you could have life we are completely unable to recognize as such. If the moon was a living thing with a billion year reproductive cycle we would NEVER figure it out.
We have no idea what we are even looking for. It’s easy to imagine we are the only things “like us” in the universe. But there could be heaps of intelligent life that is nothing like us at all. So unlike us that we couldn’t recognize each other if we were in the same room let alone galaxy.
A very wise man once told me "Life is like a bunch of people starting from the same point in the woods who are sprinting forward with blindfolds around their heads. The odds of life flourishing we're as little as we're the chances of them going through these woods without hitting a single tree, yet they did. We did."
I will never forget this because it's true. Life is definitely rare.