What we need is peace of mind. We can gain that only through the control of our mind.
Ask yourself, "Why can't I just smile and be happy?" As long as we carry the burden of the past, we cannot genuinely smile.
Even if we have everything, if there is no mental peace, we cannot lead a happy life.
We need to focus on our destination. Let the thoughts arising in your mind pass by, like watching scenery through the window of a car. The thoughts cannot affect you if you don't allow them to capture your attention.
We should acquire control of the mind and possess the power to stop it, like the brakes of a new car reduce the speed and stop the vehicle whenever necessary.
Relaxation is the technique of witnessing your negative thoughts and the hurt feelings of the mind. Once you learn this technique you understand that the negativity belongs to the mind and not to your inner Self, your true being.