Any spare change, Bud?

Some people have questioned whether the money being spent on replacing the old paper fiver with the new polymer one (and the tenner and twenty pound note to follow) is a waste as, in their view "cash has had its day".  But has it?  Will there ever come such a time?  There will always be the milkman to pay, or the gardener, or the window cleaner, or the need to pop into the corner shop for a packet of mints. And however technology advances, and may advance in the future, there will always be people, like me, who are behind the game.  I know "contactless payment" exists, but I don't know - and more to the point, don't want to know - how to use it. I'm sure the use of cash will decrease over the years, but I doubt it will ever disappear.