As someone who can recall the intricate details of The Faraway Tree but forgets to pack underwear for a weekend trip, I have often been referred to as an absent-minded professor. Being forgetful of the more useful things in life has its downsides, so when my bank issued me with a shiny new debit card a few years ago, I was happier than Rebecca Black on a Friday. No longer did I have to fret about forgetting the paper in my purse. There was only one downside; forgetting the card is as useless as forgetting the cash. In a world where the Internet is only a cellphone away, the concept of digital currency might be a solution for the Walter Bishops among us.