Why make a film about Rickles now? I was at Don's 80th birthday party, and it was such an insane, hysterical, wide range of friends. Everyone's getting up and performing, and I thought, "I don't think people even know what Don does." He's essentially been doing the same act for 48 years, but it's so unique and he's such a lovely guy and marvelous storyteller—what a great subject for a movie! The big thing was to convince Don to shoot his show because he had never let it be filmed. Everyone offered him money to do concert films or DVDs, but Don's old-school. It's a vaudeville thing.

How far is too far in pushing the comic envelope? What I've learned as a director is that the joke itself is not the issue, and that's very hard-learned. If a good friend told you a pretty vicious joke about [your religious beliefs], but it was very funny, you'd enjoy it. But if a stranger or someone you disliked told the same joke, you'd be offended. It's not the joke as much as the audience's perception of who's telling it.

So how has Rickles gotten away with being so offensive for so many years? Who knew that he had such a big black following back in the '50s and '60s? George Wallace says in the doc that Don was kind of [like] a black comedian. I said, "He was?" What he meant was that he was brash, funny, and in-your-face. He says things that you would like to say to your boss or your wife, but when you say it, you're mad. There's no malice in anything Don says. He's an equal-opportunity offender. I found it fascinating that a black audience would identify with him so strongly because it never occurred to me. I mean, Don's so Jewish to me.

Were there any juicy anecdotes that didn't make the final cut? Joan Rivers tells a story about how she was performing with him in Miami. A very important Florida judge who was apparently a pompous ass came backstage, and said, "Mr. Rickles, why don't you come have lunch and play golf tomorrow?" Joan would've said, "Oh, I'm so sorry. I have a prior family engagement and I can't get out of it, but thank you." But Don said, "Listen: One, I'm leaving town. Two, you're a putz. You're loud, obnoxious, incredibly boring, and I wouldn't play golf with you because I don't live here and you couldn't fix a ticket. No." All he did was tell him the truth.