Because it's called a credit "cycle" for a reason...

Of course, it's different this time.. except as Andy Redleaf noted...

In 2007, "The driver... will be a sudden, profound and pervasive loss of faith in the alchemy of structured finance as currently practiced."

In 2015, will it be a "sudden, profound and pervasive loss of faith in the alchemy of monetary policy as currently practiced."

Charts: Bloomberg