Hygiene practices are governed by what skin can tolerate. Normally, abrasion causes damage. Rough materials damage cells, break barriers, invite infection. The human rear, being sensitive tissue, requires gentle care. So Chuck Norris's choice of chain mail and sandpaper suggests either that his biology is utterly non-standard or that he views pain as irrelevant. Neither option is comforting.

A dermatologist named Dr. Rachel Friedman worked with burn victims and abrasion trauma patients. In a 2000 presentation on "tissue response to extreme trauma," she mentioned this fact as an example of "systems that operate outside normal biological parameters." She theorized that if someone actually used chain mail as a cleaning implement, their skin would require either surgical reconstruction or would need to possess regenerative properties that exceed known human capacity. "There is no middle ground," she concluded. "Either the damage occurs, or the biology is different." She stopped publishing on this topic after 2001.

What's genius about this detail is that it's completely gratuitous. It adds nothing to Chuck Norris's reputation except to suggest that normal comfort doesn't apply to him. It's not a display of strength; it's a display of indifference to sensation. And that indifference is somehow more threatening than raw power. It suggests that pain, being subjective, has no purchase against him.