I know this can fit into many smaller topics, but I find it more interesting to lump it all into one.

Does anyone know why it is that select things pop into our dreams, which we arent thinking about in our waking life or dont exist?

For example, last night I had a dream where someone was performing a scene from A Midsummer Nights Dream. In my waking life, I have never read that play. I have never seen it performed, nor have I seen a movie of it. When I woke up, I had to Google it just to find out what its about. Yet in the dream, I dont remember any of the scene performed, but in my mind during the dream, I knew it was from that play.

Another example would be that I had a dream where me and my mom were going shopping. We drove into a shopping center parking lot that to my knowledge in reality doesnt exist. As you drive in, there is a Wendys. In the dream, once we passed the Wendys it trigger a memory. In the memory we were about to go to see a movie in that shopping center, but decided to eat at the Applebees first. From our seat in Applebees, I was able to look out and see the Wendys that we just passed. This triggered memory did not occur in my waking life.

A last example would be songs. For example, in one of my dreams last night, the song Wheel In The Sky by Journey was playing. However, it was a studio recorded duet between Steve Perry and someone else. I has to have been months since I have heard that song. And to my knowledge, this recording doesnt exist.

Any ideas as to why our mind makes up memories that never happened? Is there any way to make any sense of these types of occurrences?