Dreaming

I had a weird dream last night. I was dreaming of person that I am not supposed to dream about. Really weird. I know this person but I didn't even think that I am going to dream about this person. Yeah I am not going to tell who this person is because you might know haha well, I just want to know why I was dreaming of someone. In my dream this person is so close to me but in real it's really not. I sometimes think maybe this person is thinking about me that's why I was dreaming of ------. LOL..