What's in a friend???

I am pondering over the question, "What's in a friend"?

You see I have been thinking.......most of my friends are true friends and seem to care about me as much as I care about them. But then there are those who because of circumstances we have become "friends" and they don't really seem to have a vested interest in me, my life, or my family. The conversations are always about them, I am always asking how their weekend was, and I truly care and like to be there to listen to their issues/drama, yet they never ask me nor even listen when I do talk about my life.

So now I am asking myself these questions... Why is it this way? Should I stop this one-sided friendship? What's in a friendship?

Shouldn't a friend care to remember or ask about my recent big ultrasound that revealed the baby's sex? Shouldn't they ask how I am feeling? Shouldn't they ask about my family? Shouldn't they come to birthday parties when invited and not only invite themselves to events for the benefits of their kids? Isn't this stuff part of being a true friend?

Now that I have realized that I have this one-sided friendship, should I end it? What would I gain in ending it? Self respect perhaps? I like and enjoy for this person.....I am just not sure they care for me.