Whenever a person travels around the world, he always keeps one thing with and within him that is his national identity. The national identity cannot be recognized only by person's language, culture or religion; it is deeply rooted within a person's genes. People can be identified by their complexion (Africans, British men etc), facial features (Chinese, Arabs etc) and sometimes by their behavior.
A country that is free and independent in this world has its own national identity that includes its culture, customs, language, dress, music, flag, anthem, currency etc. These things mainly represent any country around the world.
But the question arises that why national identity is so important to survive in the world? Man, a social animal, is different from other animals due to his brain abilities. Now, here man is compared with other animals because he can think, talk, and invent things. Similarly, man himself has made some differentiations or comparison criteria among his own kind. The national identity specifies the existence of a person.
Firstly, there were comparisons like short and tall people, thin and fat people, young and old people, strong and weak people, rich and poor people etc. These were the criteria that used to make a person different from other people. Now, it is a natural phenomenon that the strongest survives and rules. Thus, people stronger than others, started to conquer the weak and that is how the origin of nations begun. Small groups of people united and made tribes and these tribes united and made a nation.
Now, to make a unique impression, these nations started to adapt their unique styles of clothing, languages, customs and cultures etc. The land where these nations started to live was called a country of that specific nation, where everything was different from other nations, even their foods. Even then, some similarities were found. So some standard things were decided to represent a nation (i-e, flag, anthem, language and currency etc).
Mostly people do not think why a nation has these main differences? So let's find out the answer. Suppose if a Pakistani travels to China and meets a Chinese who is deaf so that Pakistani can show him his flag and can tell him that he is from Pakistan. Likewise, if a Pakistani meets a Chinese who is blind so that Pakistani can speak in Urdu or can sing his national anthem so that, Chinese can recognize his nationality that this person is from Pakistan.
Every single person on earth represents his nation and country so that his uniqueness can be identified among the people. And every person is proud on his national identity, on his existence.