The constant flux and caprice of mental events do not admit of the establishment of stable experimental conditions.
Hermann EbbinghausA poem is learned by heart and then not again repeated. We will suppose that after a half year it has been forgotten: no effort of recollection is able to call it back again into consciousness.
Hermann EbbinghausThe school-boy doesnt force himself to learn his vocabularies and rules altogether at night, but knows that be must impress them again in the morning.
Hermann Ebbinghaus