For those who don't know what a cliche is, here's the definition (given by dictionary.com):
cliche (n.)
1. anything that has become trite or commonplacethrough overuse
2. a stereotype
cliche (adj.)
1. stereotyped
You see, stereotypes and overused ideas are basically cliches.
Stereotypes have basically killed society today.
Blondes are dumb? Not all are.
All feminine men are instantly gay? That's completely wrong.
You'll be surprised at the amount of people that defy all these different stereotypes (well, the people that pretty much classify everyone by stereotypes will).