If u have not been married, it may be difficult to understand the answers to your questions. I've been married and divorced. Every marriage, every relationship, for that matter, is in some ways, different. But, here's how they work, generally.
1. 2 people get to like and r attracted to each other. Times goes by, and she gets pregnant. NO WAIT! That's not supposed to be in there!
Time goes by, and they decide to get married. The "honeymoon" phase lasts about 3 years, ( or until the baby arrives).
2. Then, each partner attains a role in the relationship. It is understood and accepted by each partner, as to what each of their roles is.
3. More time goes by. Altho the roles for each partner have been set long ago, each partner in the relationship has, or wants, change. Either thru growth, maturation, and/or finding out who they REALLY r! Or thru all of them.
4. S--- hits the fan stage of the relationship. Feeling bored, trapped, or simply resenting their partner, one of them usually wants to make dramatic changes in their life. The other partner initially blames that partner for wanting to "change the rules" of the relationship. When in many cases, that same partner has been pushing their partner in ways that caused the blow up to happen!
5. Three things can happen next:
a. They try compromises that they hope will work for both parties.
b. One partner is blamed, but they pretend nothing happened.
c. They decide it's time to break up and go their separate ways. (Which happens with over 50% of the couples that try a. and b. first, anyway.)
That's the complicated part. The SIMPLE PART is that the "blow up" can be blamed on CDing, bi-sexuality, money problems, cheating, lying, drinking, drugs, etc. Whatever, they WILL usually happen!
But it's really the nature of many people to do some things; at the wrong time, for the wrong reason, and with the wrong people. Also, it's in their nature to change their attitudes, desires, and likes and dislikes, as they grow and mature. It just isn't natural for two people to live together for their entire lives!
Jeez, I guess u hit a nerve! Sorry!