There are reasons for keeping your thoughts to yourself in class. Garrett explicates the more philosophical ones here.

His advice -- to listen to many, but decide for yourself -- is spot-on. Your life should not be a pasticcio of others'. But don't try inventing yourself. Discover yourself. If you come to the conclusion you really are a gunner, well then, embrace it. It takes all types to make up the world. But don't be one -- or any other type of person -- because you expect you ought to be.

And that's about as philosophical as I get!