I assume that this design is part of a learning experience. However, if this is a production design then you should ask yourself, Does an address really need to point back to its owner?
Joined: Jan 28, 2011
You are correct that this is part of a learning experience.There is no need for address to point back to customer.Let's say there are 2 entities A & B which have a bi-directional association. In that case I think shared primary key will be the preferred technique.