The phrase "to forget those memories" means to intentionally stop thinking about or remembering certain experiences or events from the past. Full definition
My interior spaces are about places we inhabit and our half forgotten memories of being there. (artweb.com)
We will never forget the memories made during the summer of 2011, but we are excited to see what the future holds. (lostgirlsworld.com)
Or maybe, past situations are now causing feelings of sadness, anger, or shame because you can't forget the memory though you try. (psychologytoday.com)