Perception is reality, reality is perception. If you perceive something like your spouse cheating on you the facts of it being false becomes irrelevant. I trust my wife with my heart and my life. I know she would not cheat on me. Her faithfulness I do not doubt. I see friends and coworkers struggle with jealously and I wonder if somehow I just did not get that gene? Perhaps I am the fool or too self assured that my reality is I can trust her. Until I perceive myself as the fool I guess there is nothing to be worried about.