Throughout its award-winning run, HBO's Game of Thrones introduced viewers to hundreds of characters, which might be a tall order for someone who is trying to binge.
However, for the approximately 1 in 50 who live with prosopagnosia — or face blindness — it's even tougher.
The show's deep bench of characters is one of the reasons scientists out of England's University of York used the series to study the condition that, as its name suggests, causes people to be unable to recognize faces.
Kira Noad, the lead author of the study and a PhD student at the university's Department of Psychology, said: "We chose to show participants footage from Game of Thrones because the series captivated people around the world with its strong characters and their deeply nuanced personalities."
The scientists scanned the brains of people as they watched the show; the test subjects included people who have seen the show and those who haven't, and also people who have the condition and those who don't.
The "exciting" results showed recognizing someone isn't just skin deep, researchers say.
Senior author of the study, professor Tim Andrews, said the results "suggest that our ability to recognize faces relies on what we know about people, not just what they look like."
He adds: "While it was believed that we recognize faces by learning their visual properties — such as features, configuration, and texture — our study indicates that it involves connecting a face with knowledge about the person, including their character traits, body language, our personal experiences with them, and our feelings towards them."
For the record, Brad Pitt says he's one of the 1 in 50, so don't be put off if you ever run into him and he seems aloof.