afraid of one's own shadow
afraid of (one's) own shadow
Easily scared; jumpy; timid. Everyone was surprised that Janice led the meeting with confidence, as she normally seems afraid of her own shadow. Please don't take my sister to a haunted house on Halloween—she's afraid of her own shadow.
afraid of one's own shadow
Very timid and fearful, as in Richard constantly worries about security; he's afraid of his own shadow. This hyperbole has been used in English since the early 1500s, and some writers believe it originated in ancient Greece.