But then there's the "cosmological coincidence":
Science & Technology at Scientific American.com: Supernovae Back Einstein's "Blunder"There are a number of these coincidences in modern physics. The reasons why they bother physicists are somewhat subtle, but they fall into the class of non-Copernican phenomena; things that seem to make our 'existential state' atypical.
... the finding brings to the fore another question: the so-called cosmological coincidence. Observations like this one seem to prove that regular matter and dark energy have similar densities at precisely this moment in time, even though the density of matter has been declining steadily since the big bang. Even Einstein couldn't answer why that would be.
I like to monitor this sort of discussion.