In Philip K. Dick's "A Scanner Darkly," there is a vivid depiction of a man burdened by a relentless struggle against his environment. The phrase, "Once a guy stood all day shaking bugs from his hair," illustrates the difficulties and disturbances imposed by his reality, reflecting feelings of despair and entrapment. This imagery serves to evoke a sense of helplessness that resonates throughout the narrative, highlighting the protagonist's battle against external pressures and inner demons.

This moment symbolizes the broader themes of the book, including identity, addiction, and surveillance. The protagonist finds himself in a world where he is constantly trying to rid himself of the burdens that plague him, much like the man shaking off bugs. It emphasizes the effects of a deteriorating society on individuals and the struggle to maintain one’s sense of self amid chaos and confusion, core elements that Philip K. Dick masterfully explores in the work.