Well, the meaning of the subject is like someone that really wants to know you more every-day, and hangs-out with you no matter what, and considers you a BFF, and I think you got it.
The way I would answer this is, that I never anyone interested in me, no truly loves me in a way, and it hurts every-day inside, nothing seems cool about me, So, my hearts brakes everyday seeing someone else with their friend knowing so much of one another.