You have to be careful what you think you know.

You remember only what you want to remember. You know only what your heart allows you to know.

Fear is only as deep as the mind allows.

« You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don’t know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know.

I only know what I believe.

The only thing I am afraid of is fear.

Nothing binds you except your thoughts; nothing limits you except your fear; and nothing controls you except your beliefs.

The only thing we have to fear is fear itself.

You are only afraid if you are not in harmony with yourself.

First of all, let me assert my firm belief that the only thing we have to fear is fear itself - nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance.

To fear death, gentlemen, is no other then to think oneself wise when one is not, to think one knows what one does not know.

Only knowledge that is used sticks in your mind.

Duncan, have I not told you that when you think you know something, that is a most perfect barrier against learning?

Fear is incomplete knowledge