What You Deserve

"You deserve better."
"One day you'll get what you deserve....someone who treats you like a princess. That's what you deserve." 
But what I deserve is not what I want. And I wonder where this phrase came from--what you "deserve." This phrase has followed me around for as long as I can remember. I even remember it from middle school youth groups, learning what I deserved as a 'daughter of God.' And it's followed me since then, prominently in opportunities missed. Ended relationships usher in a "you deserve better." I've even found it in my fair share of those awkward no-thank-you-not-hiring-you phone calls, "someone with your skill will definitely find a position, something you really truly deserve because you've worked so hard."
But what about what I want? 
Because the two are not necessarily the same. Rarely, in fact have I found them to be the same. In my life, or those of others. Because we can all point to someone we say through gritted teeth, "I wish he'd get what he deserves," and yet justice/fate/karma/whatever seemingly passes them by and they never seem to get what they deserve.
I've also heard it said that "we accept the love we think we deserve." This is also, in my mind, not true. To me it rings of victim-think and all too much self-pity and lack of self-esteem. It rings so very much of self, and in the end love is really supposed to be an absence of self. I accept the love I want (which is also about the self, I realize...but at least a self that acknowledges it's selfishness, rather than hiding behind it's past or psychology). I could know straight up it's not right or real or best or the highest or the most compatible or the most realistic for longevity or any other number of things, and yet I accept it because I want it. I know better. I know he's not for me. I am under no false pretense of pitying illusion that this is something I deserve. I'm mature enough and self-aware enough to know, no this is not the best. But I pick it. The same way I pick ice cream over vegetables. 
I don't understand why people use this phrase as consolation. Because the gut reaction is always the same. But it's what I want. 
Which led me to think-- Is being mature or "grown up" when what you deserve matches what you want?  If I only wanted what I deserved, would I lived financially within my means? Because I wouldn't want that $50 shirt because I know I have not yet earned it, have not yet reached that point where I deserve it due to the financial means I've achieved through hard work. If I only wanted what I deserved, would I be happy with my current work or educational situation?  If I only wanted what I deserved, would I have realistic expectations about my capabilities?  Do I want realistic expectations about this, at the risk of sacrificing dreams? What happens when what you want matches what you deserve?  Does that place really exist? Do we want it to? What's better--what you want or what you deserve?