"Je ne suis pas offensée par toutes les blagues idiotes sur les blondes parce que je sais que je ne suis pas idiote... et je sais aussi que je ne suis pas blonde."

Simplified Meaning:

This quote is about not letting negative comments or stereotypes about you bother you, especially if you know they aren't true. Imagine someone making fun of another person by saying they're clumsy all the time, but that person knows they're actually very careful and coordinated. Because they know the jokes don't really apply to them, they don’t get upset. For example, if there's a stereotype that all people with red hair are hot-tempered, and a red-haired person knows they're very calm, they won’t be offended by the stereotype. They understand it's just a generalization that doesn’t relate to them. The speaker in the quote feels the same way about jokes people make about blondes. They don't get upset because they know they're not dumb, and also, they're not even blonde! This teaches us that we don't have to let hurtful or incorrect opinions affect us if we are confident in who we are. We can just ignore them and move on with our lives.