and still never meet the neighbours

Recent results from the Kepler space telescope and studies of nearby solar-mass stars, suggest that nearly one in four stars like the sun could have Earth-size planets.

That's anything between 10-100 billion earth-like planets in our Milky Way
The Milky Way is about 100,000 light-years in diameter.

That's big enough, so that even with 100 billion earth-like planets,
and a reasonable percentage of them producing life,
and a percentage of those producing intelligent life,
and a percentage of those surviving for long enough to explore space ...
It's still possible to never, ever, meet the neighbours!
:(