haha well I don't know... I wasn't there... but a theory is a theory. There is lots of common science now that the same people hundreds of years ago thought was rubbish and impossible, and just crazy talk or wild stories. Hell, there are even people in the scientific community now that don't think gravity is real (true story). People that are "certain" we are the only life in the universe. Even with the irridium layers, I don't know how far back they go, but they do know there were several events at "regular" intervals. And maybe it's just cooincidence, but it's interesting that maybe it's not
I don't subscribe to any of the prophecies or things like that, but I'd say it's a fairly safe bet that there will be something to happen that will wipe out everything (or almost everything) again. Big rock, supernova, gamma ray burst, huge volcano... and chances are good we might not even see it coming. Probably not in my lifetime, but you never know. I think the possibilities are almost endless, and that's what makes it so much fun to theorize about