Why it's not just a piece of paper

People sometimes say to me, why get married "it's only a piece of paper".  Is it this simple?
I think not....

 A lot of couples get caught up in the fun, glamour and frivolity of their wedding day - the dress, flowers, food and music.  It is however, the ceremony, in particular the legally binding words that are spoken by both bride and groom and the signing of the marriage documentation that is in effect the beginning of a legally binding contract, which comes with significant legal obligations and responsibilities.  Getting married changes your legal and taxation status and insurance, wills and social security status change.  Laws regarding inheritance and custody of children also come into play.  

Marriage really is one of the most important contracts one will sign in a lifetime, so perhaps this is why in Australia couples are legally required to give notice of their intended marriage to their celebrant, at least one clear month before their wedding day - a "cooling off" period perhaps?