It's quite conceivable that [life] will eventually spread through the
galaxy and beyond. So life may not forever be an unimportant trace
contaminant of the universe, even though it now is. In fact,
I find it a rather appealing view.

There are at least as many galaxies in our observable universe as there are stars in our galaxy.

There are lots of ideas which extend the Copernican principle one step further. We went from the solar system to the galaxy to zillions of galaxies and now to realising even that isn't all there is.

The first voyagers to the stars will be creatures whose life cycle is matched to the voyage: the aeons involved in traversing the galaxy are not daunting to immortal beings. By the end of the third millennium, travel to other stars could be technically feasible. But would there be sufficient motive?

We know too little about how life began on Earth to lay confident odds. It may have involved a fluke so rare that it happened only once in the entire galaxy. On the other hand, it may have been almost inevitable, given the right environment.

The universe and our simple imagination cannot be linked nor compared.