Taking a page out of the Alfonso Ribeiro DWTS playbook, Nick Carter plucked fans’ nostalgia strings Monday night by whipping together a rousing routine set to “Everybody (Backstreet’s Back).†The theme for the night was most memorable year; Carter picked 1992, which was when the Backstreet Boys formed, and, as his pre-taped package noted, was also the year his dysfunctional family life was saved with a new family. It was an emotional and exciting night, one that hopefully paves the way for many a Backstreet-themed dance revival. Carter and partner Sharna Burgess promptly scored nines from all the judges — once the crowd was done fanboying and fangirling, of course. Can’t blame ’em.