Everything is rhythmic in the Universe. Cyclic and endless - waves, life and death, rise and fall.

A possible reason for the lack of encounter with other advanced civilisations is that our civilisation advances in a moment when others are in their fall, as well as their advancement happening when we've reached a state of our self-destruction, having to start our advancement all over again.

If the civilisations evolve, self-destroy themselves and start over, who can tell when we'll simultaneously reach a moment when we are equally advanced with other civilisations?