This idiom is analogous to the English expression "It's Greek to me," and expresses a total lack of understanding on the part of the person being described. The literal
meaning "not passing through a single hole" is likely a reference to the seven orifices of the head (2 eyes, 2 nostrils, 2 ears, and 1 mouth) as defined in Chinese medicinal
practices. Since information is unable to pass even one of these holes, it can never reach the person's brain and they are therefore unable to make any sense of the situation.
This idiom is analogous to the English expression "It's Greek to me," and expresses a total lack of understanding on the part of the person being described. The literal
meaning "not passing through a single hole" is likely a reference to the seven orifices of the head (2 eyes, 2 nostrils, 2 ears, and 1 mouth) as defined in Chinese medicinal.
practices. Since information is unable to pass even one of these holes, it can never reach the person's brain and they are unable to make any sense of the situation.