The actual time taken to randomly clear a hurdle actually tells you very little about how unlikely it was to clear, so long as there are several hurdles and you

The actual time taken to randomly clear a hurdle actually tells you very little about how unlikely it was to clear, so long as there are several hurdles and you condition on them all occurring (i.e., that you exist). In particular, the expected time to clear a hurdle asymptotes at a constant value even as the difficulty becomes arbitrarily hard. This is a very unintuitive but very important result for thinking about this topic. http://mason.gmu.edu/~rhanson/greatfilter.html http://mason.gmu.edu/~rhanson/greatfilter.html