For people with ADD, organization is a constant challenge. Nowhere is that more true than with something that they KNOW will be needed later. Unfortunately, for most people with ADHD, the importance of an item has no bearing on its ability to be stored and retrieved again later. That leads to special place organization.
Special place organization is when someone, whether and adult with ADD/ADHD, a teenager with ADD or ADHD, or a child with ADD-ADHD, deliberately put something important in a special place. Inevitably, the special place is chosen for being both safe, someplace unlikely to suffer an accidental throw away, and for being different than the standard location important and semi-important items are put.
When the day comes that the item is needed, it cannot be found. Sometimes, the person with ADHD won’t even remember that they put it someplace special. Even more often, the person with ADD will remember that they put it someplace special, but they won’t remember where the special place was!
What follows is a frantic top to bottom search of the house or bedroom, including all of the "usual" places objects are kept. If the ADDer is lucky, they will stumble upon the item’s special location (and THEN remember that they put it there.) If not, the object becomes yet another lost item which cannot be found when needed.
The best bet it to avoid the "special" place all together. Instead, find a way to protect the item and then put it in one of the "usual" spots. For example, put an important document inside of a page protector, or a receipt inside of a cardboard mailer. This will make sure that nothing bad happens to the important piece of paper, but when the time comes to find it, it will be easy because it will be right where you always look.