It was one of the most memorable of Rust Cohle's quotes on True Detective but what is the meaning behind "Time is a flat circle?" While Matthew McConaughey has always been in demand, there was a period of his career where he was typecast in fluffy romantic comedies that rarely stretched his talents as a performer. He made a conscious decision to seek more dramatic roles, leading to the period dubbed the "McConaissance", where he was acclaimed for his work in movies like The Wolf Of Wall Street and Dallas Buyers Club.
He also appeared in the first season of HBO crime series True Detective, alongside Woody Harrelson (War For The Planet Of The Apes). McConaughey played troubled detective Rustin "Rust" Cohle, although he was initially approached about playing Harrelson's Marty Hart. Thanks to the moody, atmospheric direction by Cary Joji Fukunaga and screenplay by Nic Pizzolatto, the show would receive widely positive reviews. While the second season of True Detective - featuring a new cast of characters fronted by Colin Farrell and Vince Vaughn - was met with mixed reviews, the third season was widely seen as a return to form.
McConaughey's Rust Cohle is a cynic who believes in the fundamental awfulness of the human race and existence itself, and while this doesn't make him much fun at a party, he delivers some pretty insightful comments. One of his most famous quotes comes during True Detective episode 5 "The Secret Fate of All Life," where present-day Rust is being interrogated about a past case and declares his belief "That time is a flat circle."
What he means by this statement is that people are essentially doomed to repeat the same cycles again and again without ever really changing. This includes circling back to the same mistakes, with Cohle firmly believing no problems ever really get solved. Diving a little deeper, True Detective scribe Nic Pizzolatto seems to be nodding towards the concept of "eternal recurrence," popularized by philosopher Friedrich Nietzsche, which points to events repeating themselves again and again over an infinite span of time.
So it's basically Rust reinforcing his bleak outlook on the world, which relates specifically to the time he and Marty were praised as heroes for taking down some meth dealers - when the truth was much uglier. True Detective's Rust Cohle may still be McConaughey's best work as an actor. It's not difficult to imagine how some of Rust's lines could have sounded clunky with the wrong performer, but with McConaughey's delivery of lines like "Time is a flat circle," they instantly become profound.