Why Is It Sometimes So Hard To Do What's Best For You?

When you start to realize that you may very well be in a relationship with the wrong partner for you, how do you muster up the courage to let go – to do what's best for you?
Are you in a relationship where deep down you know the person you're with is not the best person for you? Perhaps they don't communicate considerately – especially when things don't go their way. Maybe they're just too set in their ways and have that "it's my way or no way" mentality. And you know that without proper communication, nothing good can last. Sooner or later it will end.
Maybe they show you affection, but only when needed. They say "love you, too" way more often than "I love you." Perhaps they can't fully respect and appreciate everything about you because of their own insecurities (to which they may not realize or want to admit).
This person may have a good heart, and may even believe they know how to nurture a relationship. But after being with them, you clearly see that they may not be as mature for you in the relationship department. You consciously challenge yourself to do better for the relationship; however, your partner isn't cooperating at the same level.
With this said, you just know you're both not on the same relationship level. You know the best thing for you is to leave the relationship, but why is what's best for you so hard to do?

You may have had some great times with this person regardless of your differences. Perhaps remembering the good times and hoping for more is what's keeping you in the relationship – which doesn't help the situation.
But think about this: despite the good times, with all the other issues surfacing, is it worth it? Maybe it's worth the fun and experience for the first six months or so. But can you see a healthyrelationship with this person in the long term? If so, great! Continue on. But if not, maybe you need to reconsider.
Let me just say this: it is not your job to fix them. You don't have to try and rescue them if it means drowning yourself in the midst of it. I know sometimes it's hard to do the right thing for you, especially if you're a loyal, caring individual. But if you don't look out for you first, you won't be good to anyone else.
Saying this however, if you must stay a little longer because you feel you've already invested more time and emotion than you had anticipated, then put a time frame on it. Continue to be kind, loving and committed to the relationship, but give yourself a deadline.
Maybe you can say "I'll do my best with this person for another month or so, but I must see satisfying progress or better. And if I don't, then at least I know I did my best and I can now leave the relationship with no regrets."