7. Be honest with yourself if it truly isn't working.
Sometimes, everything can seem perfect. Your partner is incredible, your conversations are scintillating, they're your physical ideal, you get along like whoa. That doesn't mean it will work out, or is in fact currently working. Sometimes, there's an indefinable piece missing form your relationship puzzle. If you can't find it, maybe it's not there to be found. Even the most seemingly flawless relationship can fail, and we need to be able to accept that and move on.
Jon Osterman and Laurie Juspeczyk had it all. They were young (well, she was), good-looking, and in love, they were supported by the government, and he happened to be the closest thing to a god walking the planet. We all thought they would make it. Then he begins losing touch with humanity, and she realized being with a god can be a little creepy. Then their communication fell apart, then the world fell apart, and then the movie didn't end as well or as interestingly as the comic did. A relationship may look ideal on the surface, but there can be serious trouble lurking in its depths. You are ultimately responsible for your own happiness. If it isn't working, be honest with yourself.
8. People will tell you it won't work out. Don't necessarily listen.
The caveat to this bit of advice is if everyone is saying, "No, seriously, get out," and you're sporting bruises, or can frequently not remember where you were last night, then listen to your friends. Get out.
Now that we've all been sufficiently after-school-specialed, let me say that other people are dumb and petty. Old folks and relatives have been known to say helpful things like, "you'll never make it!" Particularly enterprising friends may lay wages on how long a relationship may last, and I would never, ever, be so heartless as to lay down five dollars on an obviously doomed marriage of some friends-of-friends, ever. People are jerks, though. They like to cut you down. I know I'm not telling you anything new, we're all on the internet.
I'm not saying ignore your instincts, or shut everyone out. If you feel you are in the relationship you should be, though, if you feel respected and loved and whatever else floats your boat, then screw 'em.
Looking at all the couples on this list, who would peg Homer and Marge Simpson as the one that would last? They dated in high school, got pregnant, and got married. She's repressed, and he suffers from a genuinely dangerous level of idiocy. Yet they've endured misadventures that would tear other couples apart, and still come back to each other every time. I can only hope any relationship I'm in can weather a storm as well as Homer and Marge's can.