Being that Valentines is now just three days away, I feel compelled to speak about something I'm currently going through and lessons learned from it. A relationship with someone whom I cared for very deeply ended recently. I can't say that petty differences are the reason. In this situation is boils very simply down to fundamentals, and a difference in opinion on how we both view our past looking through that lens. I have no interest in going into details or pointing fingers, but I've learned a few lessons from my experience.
Maintaining any relationship is a two way street, it's compromise. This applies to both daily interaction and deeper issues. Ladies, no matter how hard you try, you're never going to change your man -- afterall why would you want to? -- You fell for him the way he was before, not for what you thought he might be. You have to be willing to meet in the middle, synthesize your problems and commit to resolving them. You will never find everything you want in a single person. You will never agree with everything a person says or does, but if you care for that person you love them for their flaws as much as their strengths.
Let go of the past, whether it be issues stemming from past relationships, or those from your current one. If you want to make something work you can't let your own baggage infect your attempt -- because it will if you let it.
Relationships are supposed to be work, but not THAT much work. You work on doing the little things to make the other happy (or you work on showing your appreciation for the little things the other one does), you work on communicating, you work on spending more time together. When effort becomes labor you're in trouble.