Meditation is mental execise that makes the mind more powerful just like physical exercise. How? When we lift weight, it is called resistance training, because we pull more weights against the gravity than our muscles normally can, hence muscles tear up and grow further in order to be able to lift the execess weight. Similarly, when we try to meditate, all random thoughts keep coming to mind and our only task while meditating is to pull our mind from thinking all the random thoughts and bring it back to focusing on one particular thing. This is also a resistance training, resisting against random thoughts and pulling it back, again and again. As a result, our brain becomes more powerful and now it has more will power and is able to focus on one thing at a time, which is the key to any kind of success.