Pelo menos esta seria a minha razão. Fica ainda melhor, qdo é dito pela voz maravilhora da Susan Sarandon (quote no filme "Shall We Dance?"):
A) Why is it, do you think, that people get married?
B) That's interesting, because i would taking you for a romantic. Why then?
A) Because we need a witness to our lives. There's a billion people on the planet... I mean, what does any one life really mean? But in a marriage, you're promising to care about everything. The good things, the bad things, the terrible things, the mundane things... all of it, all of the time, every day. You're saying 'Your life will not go unnoticed because I will notice it. Your life will not go un-witnessed because I will be your witness'.
Aqui fica o vídeo desta cena no filme "Shall We Dance?":