Despite being a standup legend and a respected member of the comedy world, Canadian comedian and director David Steinberg still gave a sigh of relief upon hearing the first laugh at the debut screening of a new documentary profiling his remarkable career.

"It was interesting to see an audience response to it… and to hear laughs. The worst thing that can happen to a comedian is to do a documentary on your life and you’re watching it with an audience and there’s not a laugh," Steinberg said in an interview with CBC’s Q cultural affairs show.

Quality Balls: The David Steinberg Story, directed by Barry Avrich, opened Thursday at Toronto's Hot Docs film festival. 

The Winnipeg-born Steinberg, who as a standup comedian appeared 140 times on The Tonight Show with Johnny Carson, began his career in the mid '60s at Chicago's Second City. The New York Times billed him  "a cross between Woody Allen and Lenny Bruce." Later, he reinvented himself as a highly-regarded TV director, leaving his mark on shows like Friends, Seinfeld, Weeds and Curb Your Enthusiasm.

Steinberg talked to Q about growing up as the son of a rabbi and being shaped by radio programs, including hockey commentator Foster Hewitt and comedians such as Wayne and Shuster. Though funny even as a kid, Steinberg says he didn’t realize one could make comedy a career until he saw a Second City show in Chicago.

"There was a rule at Second City: don’t talk down to the audience," Steinberg recalled, and it also became his own approach to comedy.

"Here’s the rule that I set for myself, and I believe it — even on a show like Curb Your Enthusiasm: the more personal you are, the wider your audience."

With Carson, for instance, Steinberg says his shtick was completely improvised and it worked because of their rapport.

"When he is laughing at whatever it is we’re doing, those are genuine — you see in the documentary — he’s just genuinely laughing. And I went at him with his life and his divorces."

Quality Balls screens Friday and again Sunday afternoon at Hot Docs in Toronto.