What do you hold on to after foster child leaves?

My FS went home last month for the second time. He was with us for 7 months, went home for 3 months, was removed again, with us another 4 months, then went home to parents again because of a CPS procedural mistake -- even though everyone was recommending TPR. My heart breaks about the whole situation and pray for him every day. I thought I sent almost everything with him, but when I found his beanie in the laundry two days after he left, I had a breakdown. It's just a beanie but it was one of the beanies that he wore to bed because he had PTSD/trichotillomania and was pulling out his hair while he slept. Anyway...it's something insignificant, but so significant to me.