I think if you're with the right person there's no work involved at all. Doing for and respecting the other just comes naturally. You only have to work at it when the two individuals in the relationship are on different pages. When this is the case, as time passes, they grow further and further apart. That's when it takes a considerable amount of work to get back together and if you have to work at it to stay together, sooner or later you're going to resent the other party for having to do so.
Having done a bit of premarital counseling myself, I think the real problem is, people often enter into relationships for the wrong reasons and are just not honest with themselves about it. For example, if your motivation for getting married is purely physical, once that need is satisfied or is no longer possible to fulfill, the relationship crumbles.
Another problem is unrealistic expectations. I've seen people enter into marriage time and time again knowing full well there was something about their partner that they despised. Knowing and excepting this is fine, but all to often they will agree to marry under the assumption the other party will change.
Just my 2 cents.
There is some truth to that, however, when time is limited when raising kids, evolving personally & climbing the career ladder they pose trials & tribulations we hope our prior efforts have built a strong enough relationship to weather these times ...
At the same time, such a belief lead many to divorce ...
They think that b/c things aren't working out ideally - they're chosen the wrong person to marry and thus ending the marriage seems to be the only solution to the problem ...
Wrong! Not only is it ignorance, it is giving up when it seems hopeless ...
I'm certain all marriage & relationship books have a section solely on improving communication skills - this is also primary in marriage counseling ...
It is vital to understand the differences between each sex &/or the role each plays in the relationship ...
On a daily basis all around the world people talk about their relationship - trying to understand their partner - trying to resolve issues - finding ways to improve upon ...
Some hit a road block most times during a time of growth - as we gain knowledge we are never the same person ...
And rightfully so, it takes time for the partner to be onboard w/new learning - some spouses do not want to grow along side, but do want to learn to live in peace & harmony w/their partner to maintain the marriage - nothing wrong w/that ...
As for unrealistic expectations, I agree w/you ...
Unfortunately, it happens ...
Some make it work, many don't ...
I think it depends on what type of coping skills each person has as well as being aware there is always help - I'm thinking along the lines of alcoholism & drug addiction ...