My previous partner had an issue with me having a box stored away with a few mementos of prior relationships, including my previous marriage. The things I have kept are a few cards and letters. I don't feel I have any attachment to my prior relationships, but I value the memories and my time with those people contributed to who I am today.
I can understand keeping physical items could hold back healing and moving on.
How do you know if that is the case? Do you retain any keepsakes? I don't really want to get rid of everything, but I am now considering 'curating' what I have left!