What is the use of studying Russian? Russian and self-help.
On the other hand, people who can thoroughly analyze texts (oral or written) are much better at ascertaining the truthfulness of what is said or written. Most people are easily tempted by attractive advertisements and appeals as they do not realize that quite often there is nothing behind the nice words.
But this does not refer to the people having good knowledge of the Russian language. They can’t be cheated as easily as that. That is why so much attention is given to presentation at school, which is nothing but thinking over other people’s thoughts, analyzing them and drawing conclusions.
Those who often have to make speeches are well aware of the problems that may arise. If you are making a presentation or a report, it is only your fluency in the language that can captivate the audience and convince them of the correctness of your statements. Just think of the ancient speakers. They understood that well-organized speech is an art which takes time to master and is an invaluable asset.
Learning the mother tongue is not just studying language rules but immersion into the country’s culture, history as well as into the history of the Russian language. Only the knowledge of one’s roots makes one an educated person and a patriot.
This concerns any science. For example, studying syntax we understand the interrelation of its elements, their reciprocal influence and their place in the system. All this trains our minds, makes us analyze, generalize, think logically and imaginatively.