Originally Posted by albpenny

i left a massive box in my local shop yesterday. Put it down to get my wallet etc, queue of people behind me, got a bit flustered, picked up my shopping and left without it (someone shouted after me so I got it back!).

If you don't normally carry a big box, it's easy to go into a mode where you just pick up and go with what you normally carry (wallet, passport etc) and forget the massive extraordinary items. There will come a moment of panic when the traveller realises though...