This must have really sucked for the guy that lost it. But how can you not remember untill half an hour later?
http://news.yahoo.com/s/nm/20090220/..._germany_money
BERLIN (Reuters) – A German businessman lost more than 10,000 euros ($13,000) in a plastic bag after forgetting the cash in a public toilet, authorities said on Thursday.
Hesse state police said the man took the "five-figure" sum with him as he stopped to relieve himself in a motorway service station near Haiger in western Germany. He then drove off.
A police spokesman said it was not clear why the man took half an hour to notice his loss -- by which time the money had gone.