It is certainly a really difficult task for an actor to play a real person’s character in biopic. It is even more complex to play that character when the person is alive and really famous. It significantly increases the amount of pressure on the actor.
Eddie Redmayne experienced the similar pressure when she played the role of Stephen Hawking. He is a renowned cosmologist, physicist and astronomer. Redmayne incredibly portrayed the entire life of Hawking from marriage, love affair till illness in “The theory of Everything”.