how does dickens use the ghost of christmas past to reflect scrooges childhood and his memories associated to this time in his life?

The Ghost of Christmas past is a vehicle to expose Scrooge to his truth. Scrooge had to come to terms with his own past if he was to truly become a dynamic character. Scrooge sees himself as a young boy, when his father maltreated him. He sees his rejection of his fiancé in the name of money and greed. The Ghost of Christmas past exposes Scrooge to his past mistakes: he makes scrooge re-live his pain so he can become a better man.