But do not ask me where I am going, As I travel in this limitless world, Where every step I take is my home. - Dōgen

You should understand that birth-and-death is itself nirvana. Nirvana is not realized outside of birth-and death.

Handle even a single leaf of a green in such a way that it manifests the body of the Buddha. This in turn allows the Buddha to manifests through the leaf. This is a power which you cannot grasp with your rational mind. It operates freely, according to the situation, in a most natural way.

Forgetting oneself is opening oneself