Reading the Megillah Backwards

One who reads the Megillah backwards has not fulfilled his obligation. (Talmud - Megillah 2:1) One who reads backwards refers to those who treat our yearly festivals like old-fashioned relics, cumbersome observances whose time has long passed. Such a person has not fulfilled his obligation, for this wrongful attitude prevents him from experiencing the deep riches contained within the festivals.

(Baal Shem Tov)