It is not easy for everyone to study anything with concentration. But humans don’t like easy things, you know.
To study with concentration you have to develop concentration in yourself. And to develop deep concentration you have to meditate everyday. Meditation is the best way to develop concentration and patience. These two things are most essential for you to succeed.
Try to wake up in the morning and go to an open field or garden. Do some physical exercises like walking, jogging and stretching. Physical exercise is vital for you to open your mind and keep healthy. After all a sound body will have a sound mind. After that meditate for five minutes in the beginning days and increase the time length gradually.
Now you are set to study everything with concentration but one thing. Keep positive thinking. Believe that everything you are studying will benefit you in the long run. And it does. You can’t believe that the questions I read and answered in facebook groups came in the state civil service prelims! And I cleared it. You would never know when something will have implications. Perhaps you have heard the proverb “Where there is the work of a needle, what can you do with a sword?”
Keep the bigger picture in your mind. Think and feel that it will help you to your ultimate goal. Focus on the prize, skill, knowledge you want to acquire and study with zeal and enthusiast.