Is it normal i don't understand the facebook favorites list?

What algorithm had configured these people as my favorites? And what is the meaning of their order? It scares me how the people move around. I was talking to a guy a while back and after afew days fb must have figured he was my third favorite person. Then the day before him telling me he must want to be friends he moves to the bottom of the list automatically. And there's a crush I had that is fading. The more it fades the closer to the top he gets. I might just don't notice with people I'm not attracted to and I limit fb use but every time I look at the list and it bothers me that I can't know the rhyme or reason