Lately I started to believe that dreams are some sort of inner lecture that we play to ourself to live throught the consequences of our doubts and fears. Like self defense mechanism that lets us experience what we fear or what we want the most without physicaly doing it. If we want something, the dream will either give it to us or take it away, motivating you to go for it in real life. Same with fears and doubts. It lets you experience it to make you more resilient.
When you are awake. There are times when you think about your life. You start telling yourself that everything could have been better if you did the right thing. Then sleeping comes and you experience a dream where you got what you "wanted" or lost something valuable "people, property, body parts"
I don't know about incest dreams tho. I actualy had to look up what that means and if you are fuking your sister or mom. It might mean that either you were violated by them in real life. Or you want to bridge a rift between you.
Hello thar ;)