Jackie ! Intriguing. Are you really Jacqueline?
I have read that in some Native American tribes a male is given a name at birth which becomes his "child name" and when he becomes an adult - usually after a ceremony - he gets a new name which he is known by the rest of his adult life, perhaps the only exception being his mother's usuing his child name - in affection.
Then there is the whole nickname aspect of Jacqueline's query.
I had a boss whose name was Robert but he was known to all as Buzz. It suited him better than Bob or Rob or any variation of Robert.
Anyone care to add a comment/experienc?