But a pessimist knows...

A pessimist sees a bottle of Coke half empty.  An optimist sees a bottle of Cole half full.  But a pessimist knows it is full of dangerous chemicals.

A pessimist sees half a pizza gone.  An optimist sees half a pizza left.  But a pessimist knows that it will have to be put in the ref or it will go bad.

A pessimist would not marry Britney Spears because she is slutty and will probably cheat.  An optimist would marry Britney Spears because she is slutty and looks like Britney Spears!  But a pessimist knows that in a few years she will look like Madonna.

A pessimist would not marry Rihanna because she is slutty and will probably cheat. An optimist would marry Rihanna because she is slutty and looks like Rihanna! But a pessimist knows that in a few years she will look like Beyonce. Except that the optimist would point out that Beyonce still looks pretty damn good!