Sometimes it feels like the single panel cartoons in “New Yorker” magazine were bequeathed to us by benevolent beings on Mount Olympus. But there are actually humans behind it all, and we get to meet them in Leah Wolchok’s joyful documentary. At the center of it all is Cartoon Editor Bob Mankoff, who drew what may be the greatest cartoon of the modern era (Exec on phone: “No, Thursday’s out. How’s never—is never good for you?”). Mankoff allows any regular schmoe off the street to pitch their work, leading to hilarious and heartbreaking exchanges with the freaks, geeks, and merry pranksters who channel their offbeat worldviews into the magazine’s iconic black-and-white illustrations. This light-hearted and sometimes poignant documentary has a great deal to say about funny business. In Person: Subject Bob Mankoff.