"Humans are the first (and very likely only) golden ticket our planet has printed to get life off of this rock. " Not necessarily, because bacterias, the most

"Humans are the first (and very likely only) golden ticket our planet has printed to get life off of this rock. " Not necessarily, because bacterias, the most simple shape of life, can survive in hibernation in space for unknown time. And the impact of big asteroids can bring earth material into space and out of this solar system. So it is possible, that space colonisation from earth is already going on since quite some time and of course it is possible, that we were once "colonized" like this. But of course, if we can mangage to send of more advanced life, like us to other stars - than I think this is a worthy goal as well, but not none I expect to see in my lifetime. I mean even a base on mars would be cool, but that is very far from "life on mars", self sufficient and independent from earth.