Clearly you don't understand the creationComplete event. It has fired when all children of the component have been created and are finished being drawn to the screen. This event only happens once.
You could manually call your creationComplete handler method. This is not good style though. Any operations that you wish to duplicate should in separate methods which you may call from the creationComplete handler and anywhere else they are needed.
Be sure to always read the Flex Language Reference if you are unsure of how anything behaves. It can tell you a lot.