To be identified with your mind is to be trapped in time - the compulsion to live almost exclusively through memory and anticipation. This creates an endless preoccupation with past and future and an unwillingness to honor and acknowledge the present moment and allow it to be. The compulsion arises because the past gives you an identity and the future holds the promise of salvation, of fulfillment in whatever form. Both are illusions. -Eckhart Tolle
This idea that we are our thoughts, imagination, the words we say, the ideas we have, the roles we play, our beliefs etc. is not helpful.
When we identify with the wide and wonderful range of things our minds can do, we start to believe that we ARE whatever is in our mind.
When we have thoughts about ourselves or other people that we judge as negative, we tell ourselves that because we think those things (however fleetingly) we ARE those things.
We tell ourselves that because we have those thoughts and those thoughts are judged bad (by society, ourselves, others), then WE are bad.
As Tolle says, identifying with our minds does not allow us to be mindful - instead it holds us in a place of 'stuckness', mental and psychological rigidity and ultimately focuses us on what has past and what "might" happen in the future - rather than living and experiencing in the present.
If you want to live more in the NOW, less in the past and less in your idea of who you are because of what your mind tells you, you are going to have to let go the idea that you are your mind. You are going to have to see your Self as a separate entity ... your mind as a part of you but not the sum total of you.
As you separate Self from mind you will find greater flexibility in your thinking, an ease of the struggle to tame the mind, a peacefulness and calm that only occurs when we are not pulled to and fro by the workings of the mind.
It's not about silencing the mind. It's about living with its movements without attaching to them.
It's about letting go.