Have you ever thought about all the negative things in the world? Have you ever imagined all the surrealistic stuffs where some of them had the opportunity to occur and some of them Would not. Well, everyone of us at some or the other phase might have thought such things and kept us completely occupied with all the unnecessary thoughts.
Many of us will get philosophical thoughts like, who created the world? How was the first human got created, how did the elements in the nature got created and so on. While we go on searching answers for few things, we would never get it. If you ask someone what if the world wouldn't have existed, what if there was no galaxy, what if nothingness existed everywhere then what else would have been existed? Many of them will have no answers while others give imaginery answers and some others will give ridiculous answers. But you can never get satisfied with the assumptions or predictions unless you find the truth.
At that time you get to understand that there are few such things for which you can find any answers and where you have to accept them at any cost in order to keep yourself in a normal state rather than overthinking and making yourself feel low. Some others will get varieties of other thoughts such as what if the fan on the ceiling fall on me and what if I die while I drive etc all these kinds of thinkings belong to negative type.
Some other types of people start imagining things and predict the situations of the future like if I become the Prime Minister of India what would I do in the future, What would I do it I was a terrorist, what would I do if I had belonged to remote sections of the society and so on. Everyone of us can not always be positive, we can try to be positive but sometimes negativity overtakes positivity and while we go on thinking on the darker or negative side we get to know so many truths about ourselves, the people and the world.
So never stop thinking, always try to think positively but you can see a positive outcome even in the negative thinkings never forget that. Think as wide as you can, think as much as you can, think something productive, it's also okay to think something utter nonsense too. But don't let the negative occupy you.