Is it too much to ask for an "over-achiever" in a relationship?

I try and be the best girlfriend that I can be to my boyfriend. I want him to be as happy as possible with our relationship. He sometimes has that attitude towards me but not all the time. If you are with someone who does that often, then I would say that is perfect. Having that attitude isn't always the best because you need to put yourself first sometimes, you know, and that can conflict with the relationship. But often, I think that is reasonable. And in a good relationship, I believe it's very possible.