This thread will seem really cynical. This section of mumsnet is skewed because most people who post questions in here aren't happy with their marriages/long-term relationships.
I saw a film recently where the premise was that a man was employed to break up couples, but only if the woman was unknowingly unhappy. He argued there are three types of couples.
1)Those that are knowingly happy
2)Those that are knowingly unhappy - in the film it's their choice to split
3)Those that are unknowingly unhappy
It's got me thinking, out of the people in RL, how many couples do you know where you'd say they were knowingly happy, how many are knowingly unhappy, and then the biggy, how many are unknowingly unhappy?
My estimate would be about 50% are knowingly happy, and 25% knowingly unhappy and 25% unknowingly unhappy.
PS, I know this isn't a scientific survey, I'd just be interested in your general thoughts.