Your mind is an instrument, a tool. It is there to be used for a specific task, and when the task is completed, you lay it down. As it is, I would say about 80 to 90 percent of most people's thinking is not only repetitive and useless, but because of its dysfunctional and often negative nature, much of it is also harmful. Observe your mind and you will find this to be true. It causes a serious leakage of vital energy.
Don't judge or analyze what you observe. Watch the thought, feel the emotion, observe the reaction. Don't make a personal problem out of them. You will then feel something more powerful than any of those things that you observe: the still, observing presence itself behind the content of your mind, the silent watcher.
The mind, conditioned as it is by the past, always seeks to re-create what it knows and is familiar with. Even if it is painful, at least it is familiar. The mind always adheres to the known. The unknown is dangerous because it has no control over it. That's why the mind dislikes and ignores the present moment.