Jumping at one's own shadow is a perfect metaphor for living with post-traumatic stress disorder. A darkness that sets up permanent camp in your peripheral vision and won't go away, no matter how much sage you burn, or how many gods you pray to.
I remembered the thief's face vividly for a day or so, but as the days passed, I found that I remembered fewer images and more facts. Try as I might, I couldn't picture the guy's face. In other words, semantic memories were out-competing episodic ones.