People in dreams can act as symbols just like many other aspects of dream interpretation. Also, just because someone appears in your dream doesn’t mean that there’s a secret attraction there, as many people like to insinuate. Understanding why this particular person is appearing at this particular time in your life is influenced by what he might be symbolizing.
A good way to approach this analysis is considering how you would describe the person’s character, personality, and the relationship to you. From there, your actions towards this person in the dream or what was happening around you can help you decipher the significance of whatever he might be symbolizing. This analysis leans more towards the psychology behind dreams. For instance, if you are attacking this person, it might not be because you have hateful feelings towards him or feel threatened, but because you’re attacking a part of him that you see inside yourself. In another instance, if you and the other person are interacting in a romantic or loving manner, then it’s because you recognize something in him that you want to embrace inside yourself. So then the dream becomes one of self criticism/awareness. The best way to approach why you keep dreaming about someone is to think about what that person means in relation to you or your life, but not necessarily in a direct association.