13. Daniel Day-Lewis - Gangs Of New York
Daniel Day-Lewis' method acting shenanigans are the stuff of cinematic legend, and rightly so.
While shooting his role of William "Bill the Butcher" Cutting for Martin Scorsese's period crime epic, that actor refused to wear any clothing that wasn't era-appropriate. He even refused to swap out his jacket for a thicker one to battle the harsh cold because it couldn't have existed in the 19th century.
This resulted in the recently retired Oscar-winner catching a nasty bout of pneumonia, but even such a serious illness wouldn't stem his attempts to fully immerse himself in the role.
That's right, Day-Lewis initially refused medicine because it wasn't of the period, and it was only when he was informed that he could die without treatment that he begrudgingly took the doctor's advice.
There's suffering for your art and then there's straight-up madness.