Hollywood legend Mel Brooks is the subject of the new HBO documentary “Mel Brooks: The 99 Year Old Man!” 

“The thing that was most surprising about him was just how unbelievably quick-witted he still is,” co-director Michael Bonfiglio told The Post. “[He has] comic instincts [that are] so fast, and he’s still so fun. He was just incredibly quick.”

Premiering in two parts, on Thursday, Jan. 22 (8 p.m. on HBO) with a second part on Friday, Jan. 23, the doc was co-directed by Bonfiglio and Judd Apatow. 

It covers Brooks’ life and legendary career, including his marriage to “The Graduate” star Anne Bancroft (who he was married to from 1964 until her 2005 death from cancer at 73), his humble beginnings, his movies such as “Young Frankenstein,” “Blazing Saddles” and “Robin Hood: Men in Tights” and his friendship with Carl Reiner. 

Interviews in the doc include Brooks himself, reflecting on his life and work; his adult children such as Max Brooks, and various industry legends including Adam Sandler, Ben Stiller and Dave Chappelle.

Late industry legends Rob Reiner and David Lynch appear in the doc in on-camera interviews.

Rob was interviewed for the doc before his murder at 78 on Dec. 14. 

Lynch, 78, passed away Jan. 16, 2025, of cardiac arrest due to chronic obstructive pulmonary disease.

“David Lynch had stopped doing interviews because of his health. We interviewed him in October, less than three months before he passed,” Bonfiglio said, explaining that they began making the doc in “the spring of 2024.” 

Brooks exec produced Lynch’s 1980 film “The Elephant Man.” On-screen in his interview, Lynch credited Brooks with saving his then-foundering career. 

Bonfiglio said Lynch, “made an exception to his ‘no more interviews’ rule for us, because he loved Mel so much. And so, that was a really special day.” 

Reiner’s death is more recent, and sensitive, as it’s an ongoing murder case. (His son, Nick, the alleged perpetrator, is being held in a mental health housing unit at the Twin Towers Correctional Facility.) 

“Rob died after we had finished the film,” Bonfiglio said, adding that the “When Harry Met Sally” director participated in his on-screen interview in October 2024. 

“And aside from just being horrified by what happened and just in shock, of course, we immediately thought, ‘Is there anything we need to to address, given the new circumstances?’ When we went back and looked at the piece that Rob is in, I think it’s really a lovely tribute to these two families, and the closeness that they had.”

In the doc, Reiner reminisced about Brooks’ close bond with his father, Carl, who died at 98 in 2020. Bonfiglio said that he and Apatow ultimately didn’t edit any of Reiner’s segments after his death. 

“We decided to just leave it exactly as is,” said Bonfiglio.

“We felt that even in light of what had happened, Rob’s presence in the film and the things that he said and talked about took on a new meaning, and sort of tribute to him.”