We are knowingly or unknowingly creating parallel universes all the time. (I highly recommend a recent movie on this concept called 'The Source Code'. It is an amazing dramatization of this idea of parallel universes).These universes spring from our thoughts and we have hundreds and thousands of them everyday. Each thought creates its own universe. From a single thought we begin to create a reality that imprints itself on our consciuosness and whether we realize it or not, we begin to believe in that reality or those universes. This is what Maya or duality is. It is something that does not exist. But the fake universes are so convincing that if someone told you they do not exist, you would never believe it.
What is also interesting is that each of us have our own universes. So can you imagine the millions and billions of universes that exist with each of us carrying our 'set' like golf clubs in our heads! And we hit ourselves with these clubs everyday. One look in the mirror and we think how fat or ugly we are. This starts off a parallel universe without our realizing where we are unattractive and unwanted and we withdraw and hide away because that it the reality we created in that particular universe. Similary there will be other universes where we feel pain or rejection or anger or jealousy or some other strong emotion. Yes, there will be positive universes too, but they will always be fewer, because we think positively less often than we do negatively.
It is also true that these universes are temporary. They begin with the thought but lose steam or power as the thought weakens. Only consistent thoughts create permanent (or semi-permanent) universes and if these are negative they become diseases of the mind - or psychological illnesses. These are obviously toxic conditions that affect the person adversely and over a period of time can be very destructive. But even temporary negative universes create an overall negative effect on us. Can you imagine always living in a room full of disease, toxic vapours and fumes, poor light and ventilation? That is, in effect, what we are doing, choking ourselves on our negative thinking in dark universes. What of the divinity within? How can it surface, when the conditions outside remain unfavourable all the time? It sits inside, suffocating in wait.
What is to be done? The thoughts that are the birthplace of parallel universes are to be reduced. If we can have a positive thought every now and then, it will help. Staying in the present helps because before the thought has a chance to become a universe, another thought comes in it's place and the universe is destroyed before it is born. Meditation is the way to remain in the present and to increase the gap between thoughts so the proliferation of universes in our heads does not take place. Breathing helps us to keep these mushrooming thoughts and universes under control as well. As i said before, to each his own way of thought control - many techniques are there and we need to experiment with what helps us individually. However one thing to know in common is that thoughts ballooning into universes of depression are not healthy for us. Let us just begin with this awareness and contemplate on it. Next time a thought gives birth to a universe in your head - just watch it. Or write it down. Follow the chain of thoughts that ultimately leads to the creation of a whole universe in your head. It will be the first step in arresting the demon.