And those survivors dare not call it “luck,” lest the meritocracy of an intense training regimen lose its luster. Tom Brady’s ability to defy the cruel and inevitable gravity of aging gets sold, literally, as “The TB12 Method.”

Brady had gracious words for Luck (“Everyone has the right to choose what he wants to do”), but at age 42 he must surely also see some kind of moral — and manly — vindication in soldiering on as others bow out.

N.F.L. veterans who cope with a lifetime of pain, from arthritis and failing knees to headaches and memory loss, have to minimize, trivialize or write it off as an inevitable burden to bear, a mentality fortifying masculine norms. They did what they “had” to do. Indeed, apparently the biggest hurdle for the lawyer representing concussed ex-players against the N.F.L. (a case that could cost the league upward of $1.4 billion) was getting retirees to overcome their attachment to these mythologies of manliness.

Against this backdrop — with a career’s worth of rib cartilage shorn, a kidney lacerated, a concussion and a lower-leg mystery malady — Luck’s choice somehow shocked the nation. No one can or should question his toughness, but the callousness embedded in sports culture demands that we nonetheless do.

The former quarterback Steve Beuerlein gave the loudest voice to the macho take: “This I cannot defend or justify,” he tweeted. “No scenario where retirement is defensible.” Luck, he declared, “owes it to his team” to keep playing despite his injuries.

Luck is part of a generation of players unlearning those masculine “truths” about hardened self-sacrifice and the nobility of suffering. The media, incidentally, is as well.

ESPN has had to rethink its packaging of pain as pleasure: It pulled its “Jacked Up” recurring segment that spliced together neck-snapping, spleen-splitting hits and redid the “Monday Night Football” opening credits montage in which the two teams’ helmets collide in an explosion of kinetic lightning. Such tropes now look less thrilling and more ghastly.