When the answer to every question is just an internet search away, why do people still open their hearts to advice columnists? And what sort of person would dedicate themselves to answering strangers’ pleas for guidance? For Heather Havrilesky, who had always loved to hand out advice, “it was this natural, bad, compulsive thing that I’d always been doing,” she says.

This inclination developed into a weekly advice column called Ask Polly—initially commissioned by The Awl, now a mainstay of New York Magazine’s women’s website, The Cut. Frank and sprinkled with humor, the column is a rallying cry to acceptance of our flawed and fragile selves. “Look closely at the things that embarrass you the most, and the things that get you in the most trouble,” Havrilesky urges. “T...