I find it very hard to believe that will all the billions of planets and galaxies in the universe that only a single planet has life... but I also somewhat understand that the distances between planets is so incredibly vast that travel doesn't really seem possible.

I know we dream up faster than light engines, wormholes, the warp, warpdrive, etc to try and get our heads around the vastness... but unfortunately I think it's likely that those things will never be possible. On the bright side, at least we won't have to worry about humans ruining other planets.