Roger Ebert knew that he wouldn’t live to see “Life Itself,” the documentary based on his 2011 memoir. In one of the most touching scenes of the riveting film by director Steve James (“Hoop Dreams”), Ebert learns that his cancer has metastasized to his spine. The doctors estimate he only has six to 16 months to live, although he doesn’t make it that long. Ebert died in April 2013 at 70.

“It is likely I will have passed when the film is ready,” Ebert calmly predicts on-camera.

At the Sunday premiere of “Life Itself,” James broke into tears as he introduced his film, which will air on CNN. The next two hours were a sobfest, as most of the audience cried — and often laughed, too. When the credits rolled, Ebert’s wife Chaz took the stage joined by Marlene Iglitzen, the wife of Ebert’s longtime movie sparring partner Gene Siskel.

Chaz talked about how people called her a saint for taking care of Roger as his health failed after a thyroid cancer diagnosis in 2002. “What they didn’t know is how much my heart grew from having been with him for all those years, for loving him, for taking care of him, for having him take care of me,” Chaz said. During the Q&A, an audience member asked what Ebert would have thought of “Life Itself.” Chaz knew that “he would say two thumbs up.”

The stirring documentary, which was shot during what would be the last five months of Ebert’s life, includes interviews with Ebert’s director friends Martin Scorsese, Werner Herzog and Errol Morris, as well as critics A.O. Scott and Richard Corliss. Here are five of the film’s most surprising moments.

1. Ebert never got to say good-bye to Gene Siskel. In the documentary, Marlene talks about how Gene hid his brain cancer diagnosis in 1998, out of fear that Disney would replace him on ABC’s “Siskel & Ebert.” Ebert had planned to visit Gene at the hospital, but he passed two days before the visit. Chaz said that Ebert was so heartbroken, he was determined to share the details of his own health after he got sick.

2. Ebert signed “a do not resuscitate.” In the final days of his life, he sent James emails like “i’m fading” and “i can’t.” He said his hands were so swollen, he wasn’t able to use a computer. He secretly signed a DNR at the hospital without telling Chaz, which she learned about on the day of his death. In the film, she described the moment of his passing as “a wind of peace” and “I knew it was time to accept it.”

3. Ebert met Chaz at Alcoholics Anonymous. In his memoir, Ebert claims to have first talked to her at a Chicago restaurant, after an introduction by Ann Landers. In the film, Chaz says she met Roger at AA, a fact that she had never publicly revealed. And until he started dating her, Ebert had a wild bachelor streak–according to one pal, he used to court “gold diggers, opportunists and psychos.” Another buddy recalls that Roger introduced him to a prostitute he was seeing.

4. Laura Dern once gave Ebert a present that belonged to Marilyn Monroe. After Ebert presented Dern with a Sundance tribute, Dern sent him a heartfelt letter with a special memento. It was a puzzle that Lee Strasberg had given her, a gift from Alfred Hitchcock to Marilyn Monroe. Ebert later gave the puzzle to director Ramin Bahrani, with the instructions that one day, “You have to give it to someone else who deserves it.”

5. Ebert loved “The Great Gatsby.”It was his favorite book. He had his journalist friend Bill Nack recite the final lines back to him hundreds of times. Here it is, Roger: “So we beat on, boats against the current, borne back ceaselessly into the past.”