lit. when one is up to one's ears in debt, one ceases to worry about it; fig. to become numb to responsibility or stop worrying when overwhelmed by too many problems or obligations

Literally "the emperor's daughter does not worry about whether she will be able to marry"; describes a person or thing in such high demand that they do not need to worry about finding a buyer or partner

one is no longer bothered by problems or debt when they become overwhelming; literally "when there are too many lice one does not itch, and when there is too much debt one does not worry"