It's not just some random number that people throw out in conversation, nor is there anything magical or supernatural about the number itself. At the end of the day, it's just about the amount of time it takes for it to sink into a human's brain exactly who they're living with. Some people are slower on the uptake while others are a bit quicker, but seven's a nice ballpark figure to go with.
Not that there's something wrong with the other person, per se. But there are always little things, pet peeves or minor irritants, that a newlywed thinks will go away, will change, or will in some way miraculously become, if not palatable, then at least bearable.
After seven years, however, it finally hits the no-longer-quite-a-newlywed that the problem didn't resolve itself on its own, and neither did the other slew of annoyances. In fact, as a few may begin to realize, if any change at all is to occur, that change must come from within.
Most people, however, are unwilling to accept any such responsibly and, therefore, look around for the closest new person that they could conceivably find attractive in the right light.
These unfortunate people believe that their problem is their partner and, moreover, that if they choose a new partner, these problems will disappear. However, unless they accept their own responsibly in their next relationship, similar problems will resurface after seven years (if not sooner).
