Talk:A Canterlot Wedding - Part 2/@comment-13642021-20150108231534/@comment-24908786-20150111131943

Well, all the excitement for being chosen to help with Cadance and Shining Armor's wedding kind of threw that lesson out the window.

Also, Celestia knew about the threat, but when Luna took over for the night, and there was nothing new since receiving the threat, she let her duties with presiding over the ceremony make her forget about the events of Lesson Zero as well.