Repressed anger becomes a temporary madness. Something happens which is beyond your control. If you could have controlled, you would have controlled it still -- but suddenly it was overflowing. Suddenly it was beyond you. You couldn't do anything, you felt helpless -- and it came out. Such a person may not be angry, but he moves and lives in anger.
If you want to observe anger in its entirety, you will have to observe it alone, in the privacy of your room. Then alone can you see it in its fullness, for then there are no limitations. This is why I advise the pillow meditation to certain people, so that they can observe their anger fully.
