This talk from Richard Dawkins at the TED conference in 2005 just blew my mind.  Dawkins has an incredible ability to describe the limitations (or lack thereof) of the human frame of reference. He coins the term, "Middle World" as the frame of reference that we live in.  Just a brilliant talk - I highly recommend for anyone who often wonders about the so-called impossible.  It's almost 30 minutes long, but certainly worth the time.

"Evolution in middle world has not equipped us to handle very improbable events, we don't live long enough.  In the vastness of astronomical space and geological time, that which seems impossible in middle world might turn out to be inevitable."