Sri Nisargadatta Maharaj

The memory of the past unfulfilled desires traps energy, which manifests itself as a person. When its charge gets exhausted, the person dies. Unfulfilled desires are carried over into the next birth. I do not say that the same person is reborn. It dies and dies for good. But its memories remain and their desires and fears. They supply the energy for a new person. The real takes no part in it, but makes it possible by giving it the light.