It's to do with the emotions as a force due to a situation that reveals certain things that effect you. Which is not in your capacity to see, creating a negative effect. The positive is the same force that created the negative.In your dreams it is ok. When you wake up its negative. Yet the cause created the two perspectives in the first place. The prinicble you are controlled by may motivate you to understand, and so reach a higher realization about it. And so ridding yourself of the nature of this problem. Ofcourse before that happens there can be many stages to go through. Until you decide to go towards the option of asking why. When you ask, You will recieve and that will be the end of the problem. So maybe call it a lovemare. Or truthmare. (pushing you towards truth)
anyway thats the main princible for it. Any word which describes the cause.