Question your assumptions and define your terms. Tiny changes in a planet's geology and chemistry would have profound implications of the development of life and thus ideas like sentience. Even taking the temporal dimension into account, our solar system is relatively young, this does not imply that things could have started elsewhere much earlier while taking a similar enough path, especially if some of the universal constants turn out to be slightly less than constant in spacetime.
That said, I'm sure the universe will continue to surprise us.
Biting the hand that feeds IT
