Demeter and Persephone
Demeter’s daughter Persephone was picking flowers when Hades burst from the earth and carried her off to the underworld. Demeter, in her grief, made the earth barren until Zeus intervened, but Persephone had eaten six pomegranate seeds and could not leave the underworld for good. They compromised that she would spend part of each year below and the rest above, so her mother’s joy brings spring and summer while her absence brings autumn and winter.
Source: https://www.douban.com/note/612366710
Question:Why does Persephone only ate the half of the food that Hades gave her?