Does Lost have you feeling lost, even 20 years later? You’re not alone. In its journey from one of television’s best pilots to one of the medium’s worst finales, ABC’s hit castaway drama created a mythology that vexed even the fans who dissected each revelation on message boards in the late 2000s. That mythology centered on a good-versus-evil battle at its core, but complicated matters were time travel, alternate realities, mysterious numbers, dueling factions of island inhabitants, and paranormal phenomena. In fact, the narrative got so convoluted that fans had to turn to transmedia experiences and DVD extras — including the 12-minute epilogue, “The New Man in Charge” — to grasp answers not provided in the six seasons of the mainstream storyline. So as we mark the 20th anniversary of Lost’s series premiere on September 22, we’re taking a swing at some of the show’s biggest mysteries,...