Nothing is safe from the future.
You know you have lived too long when you see entire technologies come and go.
I realised that when the fax machine became the trendy new piece of life-changing technology and then mostly disappeared, replaced by e-mails and scanners.
I realised that when I first went into a large department store to see notices that they no longer accepted cheques.
When I was a child, there were two dependable professions, neither of which - it seemed - would ever stop.
One was being a watch repairer and the other was working in a bank.
People - it seemed then - would always need to tell the time and would always need to access their cash over-the-counter in a bank.
But then along came electronic watches and now people check the time on their mobile telephones (as well as taking photographs and videos on their phones).
And along came through-the-wall machines in the high street, then internet banking and now the disappearance of banknotes themselves cannot be far off - to be replaced - it seemed a few years ago - by plastic cards although now - it seems - maybe to be replaced by mobile phones which can be used in conjunction with check-out technology.
Newspapers, magazines, books, hold-in-your-hand recordings of music - all are destined for a future dustbin not too far away.
Nothing is safe from the future.
A few weeks ago, on the BBC News channel's Click programme I saw a report on 3D scanner/printers.
Today you can put a piece of printed paper into a machine and it can be photocopied exactly.
But the technology also now exists to copy in 3D.
You can put a 3D design into a computer as a file and send it to a machine perhaps on the other side of the world which will create the 3D object.
Technology advances quickly.
What can be done in one simple material today will inevitably be possible in other materials in the future. Say plastic.
OK - that can be done already. And there are various videos of 3D printing on YouTube.
There is talk of a "home-use 3D printer" market. People could use 3D printers to 'print' spare parts rather than buy then in shops or order them through the post. They could 'print' almost anything in 3D. Obviously there are current problems about machine size and keeping enough raw materials in the home for the 'printing', but these problems are not insurmountable in a few decades or less.
So, given that a plastic filing tray is quite a simple object which can be made from one supply of plastic, it would be possible to send a design from Sydney in Australia over the internet and a machine in a home in London would create it. Like a photocopy but in 3D.
If you could design an object that could be made entirely from plastic - say a mobile telephone - you could photocopy that in 3D.
Of course, maybe you could not create such a thing entirely from plastic now, but there is - as the joker lurking in the pack - graphene, billed as the new super material which will change the world.
Invented in Britain at the University of Manchester seven years ago, it conducts electricity and heat.
One of its co-inventors, Professor Konstantin Novoselov, says: "Because it is only one atom thick it is quite transparent -- there are not many materials that can conduct electricity which are transparent.'
You could stack three million graphene sheets on top of each other and the pile would be one millimetre high. It is claimed graphene could lead to mobile phones you can roll up and put behind your ear. It is tougher than diamond; it is 200 times stronger than steel; it stretches like rubber but, it is claimed, a sheet of graphene as thin as clingfilm could support the weight of an elephant.
I wonder what military implications this has. A tank built of graphene using the new stealth technology design which merges it invisibly, chameleon-like, into the background? - The realisation of an 'invisibility cloak' on an impenetrable vehicle harder than diamond and 200 times stronger than steel?
But it is not too far-fetched to imagine a 3D printer which could print out a new computer, mobile phone or TV set in your living room. Or a new umbrella or hammer or self-assembly coffee table.
The knock-on effect would be startling.
There would be little need for the transportation of parts to factories.
A car could be assembled by a car maker by printing out the parts sent over the internet by the designers of the parts. Indeed, there would be no need to 'assemble' a car. You could print it out in a factory on a large machine from a single design file held on a computer anywhere in the world.
The need for road haulage would be decimated - indeed, vast swathes of air, rail and sea transportation would become unnecessary.
And, ultimately, most shops would become unnecessary. If you can transmit inanimate objects and print them out at home, you do not need to transport and retail the items in shops.
People would presumably still require food stores, but not stationers, bookshops (which are already out-dated), DIY stores, electrical shops, toy shops, most shops. Perhaps even clothes stores might become outdated because, in time, it would be possible to print out fabric clothes at home (and adjust the sizes to perfectly fit you).
Yes, there is a problem about homes having machines of a large enough size and storing materials with which to print large objects but, in the 1960s, computers filled entire rooms and had to be tended by many technicians. Now we hold them in the palm of our hand. And they talk to you.
I remember a time before iPhones could speak to you.
Nothing is safe from the future.
And no-one.