一反既往

Explanation: A complete; past the past. Completely contrary to the previous. 　　Usage: Verb-object type; as predicate, object, attribute; with uncharacteristically 　　Examples: From now on, he wanted a reversal of past. Thesaurus:  forsake darkness and come to the light, mend one's ways, cut loose from the past and make a fresh start, To refuse the evil perfection, Gai Xian Yi Zhang, An opposite direction Antonym Group:  Qimingtouan, cast pearls before swine, cast pearls before swine, Branch road Sheep, divagate