"Holding all I used to be sorry about like the new moon holding water, niggers say."
The association of sexual purity and the moon is personified by Diana, the virgin lunar goddess
Public DomainThe association of sexual purity and the moon is personified by Diana, the virgin lunar goddess - Credit: William-Adolphe Bouguereau
New moon
Creative Commons AttributionNew moon - Credit: kbaird

This refers to the folk belief that you can predict the month’s weather by the shape of the new moon. If its horns are pointing upwards, it is said to be holding water, thus auguring a dry month. If it is facing downwards, the water is thought to pour out in the form of rain. Perhaps Quentin’s association of “all I used to be sorry about” with the moon is also based on that body’s associations with virginity.