I am dying of thirst because the hapless man in front of me in line is having trouble with his debit card. The way the hapless man in front of me in line is always having trouble with his debit card.

"Where do I punch in my password?" he asks the cashier. I stand behind him, bottled water in hand, dying of thirst, clutching a $5 bill.

"How do I erase it if I made a mistake?" he asks the cashier. I stand behind him, clutching my bottled water and a $5 bill, dying of thirst.

"Oh, I think I do want cash back," he says. "Should I start all over?"

I stand there behind him, clutching my bottled water and my $5 bill. And a thought occurs to me. What if debit cards had been invented first and cash was invented later? Wouldn't the person who brought the long green to market be treated with the same reverence as Marconi or Edison or Gutenberg?

"Wait a minute! There's no password required?" a shocked debit-card user might say, disbelievingly, using cash for the first time.

"No. You just hand them a piece of paper, and they give you change."

"And there's no way you can swipe the bill the wrong way? And there's no way your request can be denied because you don't have enough cash in your bank account? And there are no overdraft fees?"

"No, no and no."

"And there's no way some perfidious cabal of depraved Eastern European gangsters can steal your password and empty your bank account, reducing you to abject penury?"

"No way."

"Gee. Why didn't somebody think of that sooner? "

This is the very crux of the enigma. If cash had been invented after debit cards, the public would welcome it as one of the great timesaving innovations of all time.

To read the complete article, see:
The Cutting-Edge Genius of Old Gadgets(www.wsj.com/articles/the-cutting-edge-genius-of-old-gadgets-1437143832)