Is there a specific reason for this? Do we have a particular part of
brain that no other animal has?
Because you are human. So every minor change in appears looks important from skin colour, to the length of a nose, to the sounds we regularly make. If you were a lion, such minor difference would be noted but hardly commented upon. Think about this, all male lions have manes right? That is the essential display of maleness in lions. However male Tsavo lions have no mane. this is the equivalent of a tribe of people where the women have no breast.
There is no special part of the brain that is unique to humans. The structure of the brain in a mouse is essentially the same as the human. The big difference, is how big each section of the brain is.
In fact elephants and dolphin come close to matching human in cerebrum complexity. And the long-finned pilot whale, has actually more neocortical neurons than any mammal studied to date including human.
So why are us humans the guys with the guns?
Environment... no matter how smart a dolphin is, they will never master fire, because living in water does that to you. (also no hands, imaging trying to make rope with only your mouth to work with.)
And why elephant and man not waged war upon each other...(we have just not warfare were both sides used spears and swords) well them elephants have at best one hand with two fingers. No elephant, no matter how dexterous will ever learn how to knap a flint tool. Elephants never evolved hands... and us human got our hands from our ape ancestors that lived in the tree and needed limbs that could grasp.
Humans are special... but not in the way you would think. It is not because we are the most brainy animal out there, the long-finned pilot whale is more brainy. No because we are talkative social animals.... elephants talk too and they do talk to herds tens of kilometers away, maintaining decade long relationship made as calves.. Not because we use tools, birds and dolphins use tools too. Not because we have hands... many animal have hands... even non primates... like raccoons.
We are special because we can do all these things at the same time. We are brainy, have a pair of hands, tool using, social animals that live on dry land.
But that said... even with all those features.. the human species have been around for about 200,000 years. Civilization for 10,000.
Nukes, computers, and space travel.. strange as it is are very recent inventions. There are still people alive today who remembered the Wright brothers touring their new invention, the airplane. There are people alive today who saw the start of space race and the coming of the first PC (personal computer), the first nuke, the first mobile phone.
Go back just 200 and an LED flash light is tech so beyond bleeding age technology, it might as well it be science fiction (first light bulb invented in 1801. First commercial light bulb 1879).