Whatever our external circumstances, in the end happiness or unhappiness depends on the mind. Consider that the one companion whom we stay with, continually, day and night, is our mind. Would you really want to travel with someone who endlessly complains and tells you how useless you are, how hopeless you are; someone who reminds you of all the awful things that you have done? And yet for many of us, this is how we live – with this difficult-to-please, always-pulling-us-around, tireless critic that is our mind. It entirely overlooks our good points, and is genuinely a very dreary companion.
The point is that when our mind is filled with generosity and thoughts of kindness, compassion, and contentment, the mind feels well. When our mind is full of anger, irritation, self-pity, greed, and grasping, the mind feels sick. And if we really inquire into the matter, we can see that we have the choice: we can decide to a large extent what sort of thoughts and feelings will occupy our mind. When negative thoughts come up, we can recognize them, accept them, and let them go. We can choose not to follow them, which would only add more fuel to the fire. And when good thoughts come to mind – thoughts of kindness, caring, generosity and contentment, and a sense of not holding on so tightly to things any more, we can accept and encourage that, more and more. We can do this. We are the guardian of the precious treasure that is our own mind.
Jetsunma Tenzin Palmo, Into the Heart of Life