The expression "put something behind you" is used to signify the act of leaving something in the past and moving on. There are various synonyms for this phrase that can be used to convey the same sentiment. Some of these synonyms include "let it go", "move on", "forget about it", "bury the hatchet", "forgive and forget", "leave it in the past", "turn the page", "close the door on", "put it in the past", "move forward", "leave it behind", and "put it behind you". All these expressions imply that letting go of the past is essential to embrace the present and improve the future.