Acting is a strange trade.
By nature of the profession, an actor is supposed to don various masks, completely immerse themselves in a role to the point that they can convince audiences that they're someone else entirely, then discard it all as soon as the show or movie is done—only to start up again as a different character.
Many actors do this effortlessly, but others have dived too deep into their roles, losing touch with their real selves in the process. These actors have taken character acting a bit too far.
1. Joaquin Phoenix — Joker
Joaquin Phoenix confessed that preparing himself for Joker was no easy task. He lost 52 pounds in six months, which is incredibly dangerous, and he found himself fatigued and socially ostracized and on the verge of going "mad." Of course, the Joker is a famously destructive and all-consuming part. For his role as the Clown Prince of Crime in The Dark Knight, Heath Ledger locked himself in a hotel room for a month; and for the same role in Suicide Squad, Jared Leto adopted the Joker's twisted personality, sending bizarre gifts and playing strange pranks on the film's cast and crew.