Unknown person in dream says he is my brother?

hey everyone. a while ago i asked a question about this guy named lucas who kept reaccuring in my dream. i didnt know who he was, i never even met anyone named lucas so its not like i recognized him from school, the store, etc. anyways, i never saw his face. it was like a blur. recently in a dream, he told me that he was my brother but that cant be because wouldnt i recognize my own brother? does anybody know what this is?