In a recent interview, Back to the Future star Michael J. Fox — promoting the film’s 40th anniversary and his new book — said that he believes the movie is as relevant as ever, in part because society as a whole has become meaner. It makes Marty’s quick-witted battles with the bully Biff Tannen (Thomas F. Wilson) even more impactful.

Fox didn’t name names, although given the political and social moment we’re living in, it isn’t difficult to guess what bullies he might be alluding to — and how they might have a fairly 1:1 tie to Biff.

Old Biff Tannen from the "dead George" timeline in Back to the Future Part II
Biff Tannen (Thomas F. Wilson) in Back to the Future Part II

“We live in a bully culture right now. We have bullies everywhere — you don’t need me to point the finger at who, but there are all these bullies,” Fox told Empire. “In this movie, Biff is a bully. Time is a bully.”

“For me personally, Parkinson’s is a bully,” Fox added. “And it’s all about how you stand up to them and the resolve that you take into the fight with them. It’s about your resilience and your courage.”

Fox was diagnosed with Parkinson’s Disease in 1991, just a year after completing the Back to the Future trilogy, and began cutting back on his work significantly starting in 2000, when he left the series Spin City. He publicly disclosed his diagnosis around that time, and started The Michael J. Fox Foundation to research Parkinson’s and search for a cure.

Fox has written a number of books — largely memoirs, focusing on his Hollywood career and his experience with Parkinson’s — over the years. His latest, Future Boy: Back to the Future and My Journey Through the Space-Time Continuum — was co-written with Nelle Fortenberry and released last week.

There have been a number of books — official and unofficial — written about the Back to the Future trilogy, but this marks the first time one of Fox’s books has focused so heavily on that period of his life. Famously, Fox was cast in the film to replace Eric Stoltz, whose performance wasn’t clicking with the filmmakers, and had to come in halfway through production while also filming his TV series Family Ties, resulting in incredibly long work days and little sleep.

Wilson has never strayed too far from time-travel himself; he appears regularly at conventions, often posing with Fox and their co-stars Christopher Lloyd and Lea Thompson. Wilson has a popular song made up of frequently-asked questions he gets about Back to the Future, and briefly played the head of the Time Bureau on DC’s Legends of Tomorrow.

There are new, 4K remasters of Back to the Future available for the film’s 40th anniversary, including an Amazon-exclusive box set that contains a special Flux Capacitor steelbook and a copy of Doc Brown’s OUTATIME license plate.