Here are a few things that you probably didn’t know about Tina Fey: She has a nude portrait of Blaze Starr in her office. She’ll watch any TV show having to do with “transformations,” ranging from makeovers to home design improvements. In private conversations, she’s probably the most soft-spoken person you’ll ever meet. And an inordinate number of her fans are writers.

It should come as no surprise that Fey has such a loyal following among literary types. But it’s not for reasons you might expect. It’s not because she’s written for just about every major comedy institution, from Second City to Saturday Night Live, and always at their creative pinnacles. It’s not because she’s the first female head writer in SNL’s history. It’s not even because she based her first screenplay, Mean Girls, on a New York Times article and not—as with so many of her peers—on a comedy sketch.

Writers love Tina Fey because she’s living proof of our own potential. When she was hired as a co-anchor for SNL’s “Weekend Update,” and even more surprisingly, became an overnight celebrity because of it, comedy writers everywhere took notice. Her improbable stardom confirms our suspicions that if we were only given a chance in the spotlight, we would prove once and for all that we are exactly as attractive and witty as we always suspected. Not many writers are as charming in person as they are on the page. But Tina Fey has proven that we, in our dreams, are not entirely deluded.

If you watch her closely on “Weekend Update,” you can occasionally catch a glimpse of the writer who got lucky. It’s in the slight hesitation in her voice, that wide-eyed wonder when a joke gets an unexpected laugh. It’s not false modesty exactly. She doesn’t think she’s undeserving of her success. She’s just surprised that anyone noticed.

This interview was conducted by phone while Fey was staying with her parents in Upper Darby, Pennsylvania. She had returned to her hometown to finish rewrites on her Mean Girls screenplay. It’s quite possible that this entire interview took place while Fey was sitting in her childhood bedroom; the very room in which she crafted her very first joke, or first daydreamed about becoming a comedy star. The interviewer, however, felt a little creepy about asking her for details. It seemed all too likely that this line of inquiry would lead to questions such as, “Does your bed have sheets with unicorns on them?” Some things are better left a mystery.

—Eric Spitznagel

“I LIKE TO CRACK THE JOKES NOW AND AGAIN, BUT IT’S ONLY...