I think it is our past that shapes us, lessons that we have learned and mistakes that we have made, we strive to better ourselves in life. I wouldn't go far as to say 'forget your past' but more learn from each lesson it has taught you. Of course, move on from traumatic and horrific events, those moments need not to be relived, but more simple events which had any sort of implication can be used to better yourself and your judgement in the future. Most importantly, take care of you because at the end of the day, it is only yourself you can truly rely on.