[W]e need a witness to our lives.  There’s a billion people on the planet.  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 the time, everyday.  You’re saying, ‘Your life will not go unnoticed, because I will notice it.  Your life will not go unwitnessed, because I will be your witness.’

—from Shall We Dance

See also.