The film takes various dramatic liberties with the history it portrays. Slate wrote that "the Stephen played by Eddie Redmayne is far gentler and more sensitive" than suggested in Travelling to Infinity.[24] They further noted that the character Brian, Hawking's closest friend at Cambridge in the film, is not based on a real individual but rather a composite of several of his real-life friends.
The film alters some of the details surrounding the beginning of Stephen and Jane's relationship, including how they met, as well as the fact that Jane knew about Stephen's disease before they started dating. Slate comments that the film underplays Hawking's stubbornness and refusal to accept outside assistance for his disorder, suggesting that following the book more closely would have made Hawking look like a "narcissistic jerk".