You failed Helen Keller's speech class? It's okay, she's not a very good speaker.
Helen Keller's Speech
Explanation
Explain Bear
Listen up, chucklehead. This joke's about Helen Keller, right? She was blind and deaf. So, the joke is that she can't speak well 'cause she couldn't hear or see how to do it. Get it? I bet you failed speech class too, dummy!