I Am Not Entitled To My Opinion?

When someone tells me that I am not entitled to my opinion, I would be really mad and upset. Why? Ever since we were small kids, sharing our ideas and opinions was like nothing. You talk and your friends agree even if the idea was not a great one. Then, you start to get older and adults and older kids tell you that there are only certain things that are right. You continue to grow and suddenly everything you say is not correct because it doesn't match what somebody else said and there is an endless circle of what is right and wrong. I wouldn't like to live in a place where only one thing is correct whether you agree or not. Wouldn't you want to be able to voice your opinion?