Why do some people view marrying a divorced person as betrayal, even if the couple is happy?

How do you distinguish between a partner who is truly emotionally mature and one who has simply learned to use the right therapy language?
Do people need an occasional problem or crisis, to keep their mind, body and soul in shape? Are people today too relaxed and too numb for their own good?
Can you share experiences or stories where someone broke free from a narcissist's manipulation tactics like silent treatment? What helped them succeed?