Fool me once .... shame on you ...

 
See Can You Hear the Drums Beating?, Bush Flubs the Message and A Prelude to War.

There's an old saying in Tennessee — I know it's in Texas, probably in Tennessee — that says, fool me once, shame on — shame on you. Fool me — you can't get fooled again.
                                                   George W. Bush 2002

[Hat Tip: John Lynch]