Ben Affleck refused to wear a Yankees hat in ‘Gone Girl’

Christian Bale starved himself to play the creepy role of an insomniac in “The Machinist.” Daniel Day-Lewis lived in a wheelchair for weeks to play a writer born with cerebral palsy in “My Left Foot.” Robert De Niro allegedly filed down his own teeth to play a pyscho in “Cape Fear.”

Ben Affleck refused to wear a Yankees hat in “Gone Girl.”

Yes, refused. Director David Fincher asked the real-life Red Sox fan, who plays Nick Dunne, a man whose wife has mysteriously gone missing, to wear a Yankees cap in a scene during which Dunne was supposed to be concealing himself and Affleck said “no.”

“I said, ‘David, I love you, I would do anything for you,’ ” Affleck told the New York Times. ” ‘But I will not wear a Yankees hat. I just can’t. I can’t wear it because it’s going to become a thing, David. I will never hear the end of it. I can’t do it.’ And I couldn’t put it on my head.”

Affleck eventually agreed to wear a Mets cap.

While many might take this opportunity to decry Affleck for being petty or unprofessional — after all, it’s his character who roots for the Yankees, not him, a Boston-born and bred actor. But considering Affleck agreed to full-frontal nudity in the R-rated film, it seems this particular qualm had nothing to do with talent or professionalism.

Sports fandom makes people do crazy/illogical/silly/petty things. (Let’s never forget the crazed Roll Tide fan who killed Auburn’s historic trees.) And once you have a team, that’s your team. It’s a bond that’s hard to break.

Perhaps Jerry Seinfeld said it best, though, it’s really about the clothes. Affleck will never, ever cheer for Yankees gear.