Technically, techno is correct, but in this day and age, things have fallen so completely apart culturally that circumstances are not so black and white. Sometimes nothing a person does can keep a marriage together no matter how hard or what is tried. This doesn't negate the truth that marriage is a bond before God that cannot be broken in His eyes.
I think that certainly there is life after 50, and that a person can be happy, but that happiness comes from peace with God and with oneself.