Freedom of speech. How important is it?

I think it´s really important to be able to say what one thinks. But should never be afraid to say what you think of it. In the school must you dare say what you think if you think they are right, but you dare not really the because you are afraid what others will think. In society, it is important to say what you think, too, but it can be dangerous. If you say samthing that samone thas not like, you can get hurt.