Leo Babauta, at his Zen Habits blog, writes about one’s state of mind and how controlling it is a hidden source of power.

Let me give you an example. Let’s say you’re pining over a lover who has rejected you, and wishing you had those incredible moments back, where they made you feel happy, loved. But actually, the source of that love was inside of you, not outside of you. When you were with your ex-lover, they were there in the room with you, but the source of feeling loved was in your own mind, in your own heart. You made yourself feel that way, by how you perceived the situation.

That means that you have the power to make yourself feel loved. At any time. It’s always available to you. It depends on no one else.

You have the power to make yourself feel angry, or at peace. To feel hurt, or joyful. To feel connected, or disconnected. To feel accepted, or rejected.

That’s not to say that other people don’t do crappy things. But those crappy things don’t have to make us feel horrible — we can let them slide off of us, and decide how we want to feel. Sure, that’s easier said than done, but it’s still a power that resides within us.