If you have no past with XMas, then build one or share someone else's. Make Christmas a happy day for someone who has little or nothing. Get involved in programs that help the poor and lonely. Build personal and family traditions. Many people have sad experiences because of growing up in abusive and/or alcoholic families. They have more than no memories, but bad, very bad memories. They learn to replace the bad with the good with their own children and themselves.
Recapture the child within yourself.
Blondie (been there, still finding that child)