That the ones who say they care about you the most are the ones who end up treating you the worst...This is especially true in marriages although one might assume that the longer you remain with your partner the more understanding that partner will become... well... in most cases, those expectations never happen... in fact, the more that someone gets to know you, the least likely they are to like you or even want to remain with you in marriage... but, they do remain for fear of starting over... and/or... because of the fear of hooking up with someone worse...
Oftentimes, individuals who have been married before, have a tendency to want to live together for a while in order to sort out these differences or have the differences finally surface that would not have surfaced had the two individuals remained in a dating relationship... even then, and because of the theoretical love that is felt between the two individuals, those differences are again tolerated as if they were already married... hence, very little is ever accomplished by living together...
The old one becomes, the more difficult and pronounced these differences become and both parties are likely to assume that the behavior they dislike is still continuing even when it is not still continuing... as they fail to see and correct their perceptions... or, they just don't want to admit they are wrong...
Being wrong in a marriage can be devastating, especially if the other person takes advantage of that weakness or that admission. However, if one were to take advantage of that weakness or admission what does that actually say about the love that is theoretically supposed to exist between those two individuals??? It would be easy to theoretically conclude that their love did not exist at all...
Not only does this type of behavior in marriages cause affairs to take place, but it also causes the two individuals to simply begin existing in two separate environments whether those environments take place inside the home or outside the home does not seem to matter. typically, they will involve themselves in activities that they may or may not like but are willing to accept just to get away from their spouse...
Conservatively, I would estimate that this happens in about 80% of our current marriages, and no doubt the main reason that the divorce rate for the last 20 years has hovered around 50% which includes marriages in the Bible Belt.