Related:

• The most difficult thing in the world is to know how to do a thing and to watch someone else do it wrong without comment.
  -- Theodore H. White...
• The most difficult thing in the world is to know how to do a thing and to watch someone else do it wrong without comment.
  -- Theodore H. White...
• The most difficult thing in life is to know yourself. -- Thale
• Do not attempt to do a thing unless you are sure of yourself
  but do not relinquish it simply because someone else is not sure of you. -- Stewart E. White...
• The job of the leader is to make it easy to do the right thing, difficult to do the wrong thing.
• In a social situation, the most difficult thing to do is usually the right thing to do. Meyers Law
• The most merciful thing in the world is the inability of the human mind to correlate all its contents.
  -- H. P. Lovecraf...
• Adultery - two wrong people doing the right thing.