This is it I think.
People disbelieve other life outside of earth with certainty, when they can't even master basic mathematics. The human brain is pretty pathetic isn't it?. Animals are more in tune with this earth than us.
"The universe has to have an end" Not necessarily.
We have evolved and improved as a species through the collective contributions of billions upon billions of people down the years.
Then you've Dave from accounts thinking alien life is just a bit silly. So I guess he can comprehend the universe in his one dust sized brain eh?. No one can.
It is more enjoyable to be an optimist than a pessimist on this. It is why we are given imaginations. Not to think of the next dead girl storyline in a danish drama, but something bigger!.