Peace does not require constant effort. 

Only the absence of peace requires effort.

My life experiences have taught me that my peace is contingent upon acceptance of my mind and my heart just as they are and acceptance of life as it is,  and not contingent upon reaching some state of mind that is superior.  The good feeling that I enjoyed when I practiced Knowledge is not different from the good feeling that I feel now.  I don't have to do anything at all to get in touch with the feeling of the heart and the feeling of peace other than to be awake and open.  It does NOT require constant effort.  It is very easy. 

What Knowledge does require is a lot of rationalisations and adherence to a strict philosophical teaching.