Confused

This morning I discovered that someone who I love, who I valued as a friend, who I thought was taking a break from facebook, instead had deleted me and blocked me. To say my feelings are hurt is putting it lightly. Confused, sad, hurt. I just honestly don't understand it. I DO NOT GET IT!
I have deleted people, heck I've even blocked a couple...although they were never people I considered friends and if I was, I was honest enough to tell them why through a PM, because at some point they were someone I cared enough about to call friend. I do not call people friends, unless I mean it.
What are others take on that? Ultimately when the email you have no longer works, you lost their phone number, because you lost all your contacts at one point. I just would like to know why.
It's obvious that she meant more to me, than I meant to her. I can accept that, I have friendships where I think I may mean more to the person than they mean to me. It doesn't make the friendship less though. It also means that if they did something I would let them know through a private message or something. Heck just call me out in public, at least then I know what in the world is going on.
I know I have a beautiful family and precious friends who are TRUE, REAL, and most importantly, HONEST friends. I thought this person was one of those friends. It sucks when you discover you were wrong about a person. VERY wrong.