"If you search for awakened heart, if you put your hand through your rib cage and feel for it, there is nothing there except for tenderness. You feel sore and soft, and if you open your eyes to the rest of the world, you feel tremendous sadness. This kind of sadness doesn't come from being mistreated. You don't feel sad because someone has insulted you or you feel impoverished. Rather, this experience of sadness is unconditioned. It occurs because your heart is completely exposed. There is no skin or tissue covering it; it is pure raw meat. Even if a tiny mosquito lands on it, you feel so touched. Your experience is raw and tender and so personal.
The genuine heart of sadness comes from feeling that your nonexistent heart is full. You would like to spill your heart's blood, give your heart to others. For the warrior, this experience of sad and tender heart is what gives birth to fearlessness. Conventionally, being fearless means that you are not afriad or that, if someone hits you, you will hit him back. However, we are not talking about that street-fighter level of fearlessness. Real fearlessness is the product of tenderness. It comes from letting the world tickle your heart, your raw and beautiful heart"
Shambhala ~ The Sacred Path of the Warrior by Chogyam Trungpa, p45-46