It is not possible to set out to make a positive difference in this world. This is for the simple fact: you have no idea what effect your actions will have.

You have no idea whether your action will result in something that ultimately ends up being positive or negative. You also have no idea what making a positive difference really means. You may think you know, but "a positive difference" is a very relative term.

Plus, you can guarantee yourself being completely wrong by having a strong conviction in your belief that what you are doing is making a positive difference. It is irrational to unwaveringly believe in something that you cannot possibly know the outcome of. Humans are fallable, and any idea or interpretation that they think of has a chance of being completely wrong. You have to accept that fact and thus you cannot have an unwavering conviction that what you are doing will make a possitive difference.

Thus, in summation, it is not possible to set out to make a positive difference in this world.

This is the seed of an idea. It is very rough at this point but it is a good thought. It needs to be explored.
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You get robbed. What are you supposed to do?
You are supposed to call the police.
A financial deal goes sour. What are you supposed to do?
Get a lawyer and sue.
You are hungry. What are you supposed to do?
Go to the store and buy something that a farmer grew and a manufacturer assembled and cooked.
You are young and ignorant. What are you supposed to do?
Go to school and get lectured to about material that was decided upon for you.
You have no food or shelter. What are you supposed to do?
Get a job to earn money to hire other workers to produce food and build a shelter.

We are living by proxy. We are living indirectly. What happened to just plain straight-forward living? What happened to defending ourselves? What happened to standing up for our own rights? What happened to going out and seeking knowledge first-hand? What happened to doing something, anything, directly?

We have become weak and ineffective. We don't do anything anymore. If you die actually doing something, so what? At least you actually "lived". A tiger wants food. It goes and kills and rips the flesh off of the bone with its teeth. It wants to sleep, it finds a covering and sleeps under it.

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Do not be fooled by the rich elite who tell you that we live better than anyone else on earth. You are their penned up herd of cattle which they feed upon when hungry.

Why are humans so physically lacking in strength and deficient in natural "tools"? Other animals have sharp claws, sharp teeth, powerful limbs, specialized tools such as trunks, etc. Why does man lack all of this? Man is pretty feeble. It is difficult for a man to kill another man without using specialized tools. It can be done, but it is difficult.

When primitive man got into a fight with another primitive man, they tried to beat each other to death. This made each tired. And without any natural weapons or natural armor, both got superficially bruised and fell down and eventually got up and walked away. If they had razor sharp claws, they would have killed each other. We are no doubt an aggressive species and we will fight one another. If not for our feebleness, perhaps we would have killed each other off early on in the history of our species.