Accumulated wealth, filthy lucre or the smell of money?

Over the years I've accumulated a pretty good assortment of fairly tatty banknotes from overseas trips. Arriving home there's generally the odd coin or note remaining that was either lurking in a pocket or too small to spend at the airport or perhaps even too torn or disheveled to be accepted.  There are stories in these notes - memories of adventures or encounters, some good and some bad.  Unlike the UK, where currency is taken out of circulation by the banks when it becomes worn, many countries keep notes in circulation until they literally disintegrate.  In remote areas I've been given change for purchases in notes so disgustingly falling apart it's almost impossible to tell what they are.  Passing through so many hands and stored in so many pockets - banknotes frequently become filthy objects, no doubt a vector for disease and infection in impoverished countries.  Despite all this they are fascinating objects frequently portraying something telling of the country they which they originate.