Fred Rogers passed away 15 years ago. His TV show began in the 1960s and most people’s recollections of it are through the fuzzy lens of their childhood. As a result, a personal metaphor of Mister Rogers (unruffled? nice? wimpy?) is clearer to most of us than the actual person or PBS program. The 2018 documentary “Won’t You Be My Neighbor?” is a welcome reminder that there was a whole lot more depth to the man, and the show. Morgan Neville tells the story thoroughly and fairly, examining topics (race, sex, etc.) that would have sidetracked a less disciplined filmmaker.