In his one-man stage show, the late Charles Nelson Reilly would talk about his mother. It wasn’t exactly a loving tribute: This is a woman whose favorite word was “no,” who shouted racial slurs out their Bronx window, and who was supposedly so hated in the neighborhood that she carried around a baseball bat whenever she ran an errand. During one battle with her son, Mrs. Reilly shouted, “I should have thrown out the baby and kept the afterbirth!”

You can hear the crowd gasp after that line in The Life of Reilly, an 84-minute film that captures highlights of the comedian’s three-hour-plus monologue. And Reilly rebukes them: “Did you think it was all going to be game shows?” That gets a laugh; subsequent stories about how his mother’s dream-crushing stubbornness ultimately landed his father in an institution silence the theater. It’s not far into Frank Anderson and Barry Poltermann’s documentary before you realize that no, this surprisingly poignant performance won’t be burbling over with Match Game–ready froth.

At first, you probably won’t recognize Reilly—instead of a clown in a bad toupee, Rocket Man glasses, and sailor suit on stage, he’s a frail-looking, balding senior swimming in a button-down and khakis. There’s a reason, and it’s not sudden aging: It’s probably been forever since you’ve seen the guy. This show, Reilly’s final one before his death last May, was filmed at a North Hollywood theater in October 2004, and the directors realized the actor had fallen into obscurity, inserting footage at the start of the movie of a street poll asking people if they knew who Charles Nelson Reilly was. (The majority replied that the name sounded familiar, but few could definitively say.) Reilly himself was aware that his star had significantly dimmed, beginning his monologue by gently proclaiming he’s at the “twilight of an extraordinary life.” He uses the word “twilight,” he continues, based on run-ins with fans, such as the excitable lady in a supermarket who saw him and shrilled, “Oh! I thought you were dead.”

So the performer may not resemble the guy who shows up on GSN in the middle of the afternoon, but the voice—whether he’s doing the grocery-store lady or just ad-­libbing an aside—hasn’t changed a whit. And that distinctive sound, borderline-hysterical and always used for laughs, makes some of the tales Reilly chooses to share even sadder. Co-written by actor Paul Linke, Reilly’s monologue is, as the title suggests, an autobiography, and it took a while until his life became bearable. After his artist father was institutionalized, having started to drink heavily after his wife forced him to turn down a job opportunity with a then-unknown Walt Disney, the Reillys were broke and moved to Connecticut to live with a relative who was a recent lobotomy patient. (“Eugene O’Neill would never even get near this family!” Reilly says.) His mother discouraged his desire to act. So did an NBC exec, who told him, “They don’t let queers on television,” cutting short a meeting that Reilly was certain would be his break.

The Life of Reilly isn’t all bad news, of course, but even when Reilly is talking about his fascination with film or his first steps toward success, it’s with a reverence only occasionally punctuated by a quip. This is a story about all wide-eyed dreamers as much as it is about him: When Reilly reads off the roster of his classmates in a New York acting class for the dirt-poor—Jack Lemmon, Frank Langella, Hal Holbrook—it’s a simple act that’s hugely inspiring. (It’s particularly so when he mentions that Holbrook, carrying a white wig in a paper bag, was doing Mark Twain even then.)

There are several components to his set—some living-room furniture, theater seats, a podium, and a prop table—but you get the feeling that the performance would have the same effect even if the stage were empty. (More distracting, however, is the directors’ insertion of random footage throughout the monologue—there are more grainy shots of trains, it seems, than clips from Reilly’s television career.) One-man shows are deceptively relaxed; a good performer makes you feel as if you’re just catching up with an old friend over drinks, unaware that there’s a script feeding the recollections. In this regard, Reilly’s an ace, appearing to simply make conversation while effortlessly re-creating characters from his past, sometimes preceding his descriptions with a “C’mere!” or “See her?” You do, and with all his affectations stripped away, you see the genuine Reilly, too.