In The Miracle of Mindfulness, Vietnamese Zen Monk Thich Nhat Hanh describes the first part of the meditation practice: as you observe your thoughts, do not participate in them which leads the observer to be beguiled with the emotions, fantasies and regrets.

The essential thing is not to let any feeling or thought arise without recognizing it in mindfulness, like a palace guard who is aware of every face that passes through the front corridor…

When we are angry, we ourselves are anger. When we are happy, we ourselves are happiness. When we have certain thoughts, we are those thoughts.

We are both the guard and the visitor at the same time. We are both the mind and the observer of the mind.

Therefore, chasing away or dwelling on any thought isn’t the important thing. The important thing is to be aware of the thought.