Broken Record

I have learned a valuable lesson from past relationships (friendships and "beyond"), that sometimes you can only do so much. Relationships are two sided; a one-sided relationship is called an imaginary friend. The "unspoken rule" of any relationship is that each side puts an equal amount of effort into the relationship. Even in the workplace this is applicaple; for example the employee fulfills one's duties and the employeer in return gives a paycheck. Though friendships, and dating relationships rewards are not monetary, the rewards are much more meaningful and benefical.
I have found out that I continually try to please others, I have a classic case of what society likes to call "people pleaser". I am currently working on that, and wonder when does pleasing people become a flaw of one's personality. Also, can I completly change that or isn't permanetly engrained into my personality and my way of thinking.
The dillema I continually find myself in is putting effort into relationships, whereas most people would have given up long before. And I ask myself, why?! Once again I think it falls back to being a people pleaser.
I have made myself a promise, not to find myself making the same mistakes. One can only do so much before you just break away even from the most promising relationships (friends or otherwise). After a while its like a broken record....doing the same things over and over with no sense of ever moving foward or change.