Ghost of the past

Why is the Ghost of Christmas Past young, small, cloaked in white and shining bright? What does he mean when he says that Scrooge made his cap and has forced him to wear it?

Maybe because in Christmas Past Scrooge was young and still innocent and had happy possibilities ahead of him...and then started changing and would have to wear the "cap" of what he had become and the choices he had made.
-Bookworm

I have no idea. I was hoping to get some insight from you all.
-Annegirl