I check for my child everyday at pickup time. He loses things once every week or so and also hates being held responsible for it. He say things like "someone took it away" when it is not the truth - he probably forgot his lunchbag at the lunch area or left his water bottle in class. I am working on reminding him that historically, all his lost items were found again in places where he left them by mistake and that nobody ever wants to take other kids' used water bottles or lunch bags. He is able to remember better as the school year progresses and the routines are more familiar. I put his checklist in a dry erase pocket and ask him to check off the items everyday. I only hold him accountable for using the check list every day and not for items lost as he is a "sensitive" soul too and gets upset even by changes in my tone of voice when I ask about missing items. For items lost, I check at pickup time and go and look for them for him in the beginning of the year. He does not want to walk around campus with mom in tow looking for things, so he quickly gets into the checking habit in a few weeks and then we have better results!