It all depends how hard you and your partner are willing to make it work.
That's why we got marriage, you basically tell each other: "You are not running away and I am not running away."
You work through it, through thick and thin, no matter how desperate the situation seems to become.
And I think the key is, you don't ever let your relationship get worse, not even a little, so you never get to the point of no return
@EvilLocks is talking about.
You stay awake and you pay attention, even to the things that seem irrelevant.
If you feel one ounce of resentment, you work it out,
right now. Well, you do it privately with your partner of course.
I think this is what makes my relationship works so well. If something bothers my girlfriend, she will tell me, immediately, that's just how she works.
It took me a while to realize that this was why she was piratically never being a b**ch, or silently mad at me.
She's always at peace, and I'm always at peace because we work our problems out before they start becoming bigger and harder to solve.
The hard part is to become aware of what truly matters. And the partial answer to that is
everything to some degree.
Listen to yourself, pay attention to your negative (and positive) emotions, and most importantly,
talk. Get it out there, even if utter stupid sh*t, your partner is going to be there to tell you that you're being stupid (like I often am on this forum
).
But never let your anger and frustration brood for too long, this is how all seemingly functioning and happy relationships start to fall apart.