Let go of the past, let go of the future, let go of the present, and cross over to the farther shore of existence. With mind wholly liberated, you shall come no more to birth and death.  - The Dhammapada (334-359)

These lines from the Dhammapada (a series of early and very poetic Buddhist teachings) have always moved me. But what does it really mean to “let go” in this way?