A Christmas Carol is an allegory, and the compassionate, soft-spoken Ghost of Christmas Past represents memory. His appearance is strange, and most notably fluid, indicating the constantly shifting nature of remembering. That the ghost appears to be both childlike and aged, “like an old man,” suggests memory serves as a bridge between different points in life.
The light coming out of his head, combined with his flickering appearance, likens him to a candle; indeed, he uses a cap to dim the light, almost like one would use a candle snuffer. This aspect of his appearance is indicative of enlightenment; examining his memories enables Scrooge to learn about his past, to understand things about himself he might not have otherwise. However, Scrooge forcibly attempts to put out the ghost’s light when his memories become too much for him, symbolizing his fear of self-knowledge. For Scrooge, reconciling the man he is with the boy he used to be is painful. However, despite Scrooge’s rejection of the past, the ghost’s visit marks the beginning of his transformation, initiating the removal of Scrooge’s hardened exterior.