I was always a hopeless romantic, and I would always let my heart dictate what I did. But this isn't a good strategy. It teaches us to betray convictions, and breeds resentment.
I've been focusing my energy on finding the perfect balance between being easy-going, open-minded, and having a 'take no shit' attitude. That is, I have to defend myself (so as to never become bitter), but also know when to step down (so as to be fair). I have to be ready for life as it comes (and be easy-going), and not reject it when it's not what I hoped it would be (because it's so easy to be hard on people for not giving you what you wanted from them).
It's the only way to go forward that makes sense to me. But it's hard. Sometimes I don't know if I'm being unfair when I'm defending myself, or letting people walk all over me when I don't.