Why do people have a nickname?

Nicknames are usually made up to simlify a longer name. I have a foreign friend whose name in Milenkomajenovic, from Yugoslavia, but we just call him MJ or Mil. Also, nicknames can be used because someone doesn't like to be called by their birth name.

Or maybe they don't like their name? I guess that there are many causes why people use nicknames..

Good question...there may be more reasons than what u already mentioned.One reason could be that some person might find his/her name quite unconventional..difficult to be adapted easily .Second reason is that one needs to keep the real name a guarded secret...

In the case of my family, we all have nicknames and there are terms of endearment and love. It is a special name that we use only within the family and in fact none of us will respond if someone outside our immediate circle calls us by our nickname. With our son, he has a special family name, plus those he went to school with call him another name, mainly because they couldn't pronounce his surname when they were young. His employers gave him another name because our son and their son had the same Christian name. All are special and unique but we know who it talking depending on what nickname he is called by. For others the nickname could be from something they do or like but it is personal in nature.

Nicknames are usually made up to simlify a longer name. I have a foreign friend whose name in Milenkomajenovic, from Yugoslavia, but we just call him MJ or Mil. Also, nicknames can be used because someone doesn't like to be called by their birth name.

In the Bible we can't find surnames but there are many characters with the same name for example Maria. There are many Marias there and to identify one from the other, something is attached to the name. One Maria lived in Magdala and therefore she was called Maria the Magdalene. There are also many Johns and one of them is identified as John the little or John the beloved. Nicknames are usually given to distinguish one from the other and so we give nicknames to whoever we want to to show whatever too not just for intimacy for there are some for hatred and sometimes because the actual name is too long.

I think because it is put on themselves or by friends where the parent named them before they knew them

All those reasons are true, I agree with that.

it is for more intimacy.