Well, for me it means a bunch of things.
On the positive side, it means that I now have a reason for why I acted much in the ways I did my whole life. It gives me a base to work from so that I can aknowledge and work on issues and behaviors.
On the negative side, I can't say I much like the diagnosis. I mean, I really don't want to be borderline. But I am, and even in reading books its like looking at a mirror of myself. I guess I don't have to like it in order to work on it and understand it.
Don't let the diagnosis get you down! It is just a label for you to use to try and help understand the things that go on with us.
And, take things one step at a time