A belief held by children. The point where one runs out of steam.
Happiness is the illusion of the perpetually deceived.
Also someone who believes that we live in the best of all possible worlds. A Pessimist is someone who fears that the optimist is correct in this assertion. Our society should be purged of the perverts who provide the media with pornographic material while pretending it has some redeeming social value under the public's 'right to know'.