Why does culture exist?

As animalistic behaviour of humans reduced.he started thinking about to live in a particular place(instead of searching food and keep on moving) uptill his death.but stay in a place for a very long time is boring it's the human behavior.so to overcome this he start adapting some cultural activities that 'll make him happy.and when he got happiness he start loving things that 'll bring him happiness and he tried to make those things his own.at this point his cultural mind start developing and so many relationships,worships,jobs,festivals,dressings,talkings,musics etc have created.