Even within the Milky Way, most "earthlike" planets in habitable zones around sunlike stars are on average 1.8 Billion years older than the Earth. If the "heavy bombardment" period at the beginning of a rocky planet's life is approximately the same length for all rocky stars, which is likely, then each of those 11 Billion potentially habitable planets still had 1.8 billion years during which life could have formed. On Earth, life originated almost immediately after the bombardment ended and the earth was allowed to cool. Even if the probability of each planet developing life in a period of 1 Billion years is mind-bogglingly low, we still should expect to see life forming on some of them given 20 Billion Billion planet-years.