Failure.
The hardest part of life is dealing with your own failures. You cannot shift blame when you let yourself down. The entire microcosm of your personal experience is under your control, but somehow you fail to live up to your own expectations.
Dark clouds of disgust will swirl through your mind as you angrily search for an outlet to express your disappointment in yourself. But there are none. You have no recourse, no means to externalize the self-loathing. Or maybe you do. Maybe you project your shortcomings on others and affront them for no particular reason. Not me. I become despondent and let the self-disgust eat away at me until I long for relief from my own scathingly afflictive scrutiny.