Why do we allow racism to exist?

i know you may to yourself: well we can't stop it but it is possible to stop. why do we as a species and supposedly the most intelligent creature on the planet. it seems to be more and more rampant with each passing year but we act as if it doesn't exist. im a mixed raced kid and i catch **** from both sides. Can i get an honest straight forward non-trolling answer? im sorry im struck by a fowl mood.