So...why is Free Speech so important?

Why speak up about things that don't seem to affect you?

Pastor Martin Neimoller's view in one version of his quote answers that question.

He supported the Nazis until he realized (too late) what they were really about and was sent to Dachau concentration camp. 

"First they came for the Communists,
  and I didn’t speak up
    because I wasn’t a Communist.
Then they came for the Social Democrats,
  and I didn’t speak up
    because I wasn’t a Social Democrat.
Then they came for the Trade Unionists,
  and I didn’t speak up
    because I wasn’t a Trade Unionist.
Then they came for the Jews,
and I didn't speak up
because I wasn't a Jew,
Then they came for me,
  and by that time there was no one
    left to speak up for me."