With the best intentions in the world I carefully remove and replace items from my rucksack during an evening, putting important stuff in carefully chosen pockets and positions in the pack.
Now, after a few beers I start to think "where's my torch etc?", and out comes the whole contents of the bag. After a few of these rummages I chuck all my stuff under the hammock and have a doze, only to awake to what looks like a post Glasto, pikey field type view of everything I'd brought with me but couldn't find scattered everywhere. That's my storage system anyway, works (or occurs) every time.
