For as long as I can remember, about half of my dreams involve something a bit odd which I'll describe below. I'm curious to know whether this is normal or not, if anyone else has experienced it, and any ideas on why this may happen.

There's usually at least one person in my dreams who becomes a different person one or two times throughout the dream. Usually, I'll know all of the people in real life. What I mean is, a dream will be going along normally with a certain dream character. But, after a while, that person will change into a different person, yet retain the same role in the story as the other person. I don't realize that anything has gone amiss in the dream. My dream-self is clueless and simply acts as though this is who the person was all along, once his or her identity is changed.

Sometimes, both people play similar roles in my life, and it might make sense for my mind to get confused. For example, a dream might involve my boyfriend, and then later on that person changes to my ex or a guy I used to like or something. But other times, the people have no apparent connection at all. It isn't rare that someone is replaced by the someone of the other gender, or that the two people have completely different personalities and relationships to me.

I won't realize in the dream that this is odd. I'll only realize it afterward, while writing it down, and then it becomes awkward to write down. I'll have to make a note such as "personA was now personB," and I always feel like anyone reading won't understand what I mean by that.