'Everything that can be invented has been invented." So, according to an oft-repeated story, said Charles H Duell, the commissioner of the United States Patent Office, way back in 1899. Sadly, it's an urban legend. There's no evidence that Duell, or anybody else, said any such thing. Yet today more than ever, it's easy to imagine why somebody might say it.
Certainly, there are still discoveries to be made in science, especially in medicine, where cures for many terminal and debilitating diseases appear tantalising close but frustratingly far away. We also need to find ways to feed the seven billion people who now inhabit our fragile planet. But, in terms of innovations that just make our lives easier or more fun, don't we have enough already?
Quite often, when confronted by breathless revelations in the media about a new product, I scratch my head and say to myself, "Do I really need that?" Of course, there are also occasions when I think, "Yes, I must have one of those."
Usually, however, common sense gets the better of me before I get my credit card out of my wallet. I try to spend my money wisely, to save sensibly for my own future, and to help my family and those in need - but there are also times when I get the irresistible urge to buy a toy.
In this, I am not alone - and nobody knows that better than the people in Cupertino, California, where Apple has been in the business of making "must-have" personal technology for the past 36 years. Even the death last year of founder Steve Jobs hasn't diluted this juggernaut's grip on the popular imagination and our pocketbooks.
As I write, the internet is abuzz with rumours about the iPad 3, which is expected to be announced on March 7 and be available for purchase in the US the following month.
I've been reluctant so far to part with my hard-earned cash for an iPad. In its first incarnation, it just seemed like the overgrown version of my four-year-old iTouch iPod. The second iPad piqued my interest, because it had a camera and a more powerful processor, but not sufficiently to prompt me to purchase one.
So this time, it's up to Apple to make a technological offer I simply cannot refuse - even if I'm barely able to understand what the promised "retina display" actually is, let alone convinced that it will change my life.
I know that, eventually, I will relent and buy one of these devices. And, as many economists will tell you, it's important that I do. Consumer demand makes the world go around, you know, and those of us who can afford to consume are doing everybody else a favour by doing so. No iPads sold, no jobs for all those people in the component factories.
But, to return to my original proposition, given that we lead comfortable lives already, possibly to the extent that technology is making us lazy, do any of us actually need a new thing that doesn't do much more than the thing we already have (and didn't really need)?
When the iPhone 4S was released last year, I read that it had 200 more features than its predecessor. That's about 197 more features than I actually need in a phone, but I was impressed nevertheless. As far as I can tell, the significant advance is Siri, the "intelligent personal assistant", which allows you to behave in public like a crazy person who talks to an inanimate object.
But it's not just phone and internet devices that are evolving. Many countries in the developed world already have high-definition digital television, and some are introducing 3D sets. What next? The Holodeck from Star Trek - where you can immerse yourself in any "reality" you like - suddenly doesn't seem so far-fetched, especially in an era of motion-controlled video games.
But what's in it for me? As I get older, my eyesight and my hearing will diminish as screen resolutions and audio technology improve, so they won't make much difference to my appreciation of what I'm seeing and hearing. On the flip side, there's every chance that the latest advance in gaming might be applied to some medical device that will improve or prolong my life.
On balance, I think Charlie Duell wouldn't have said we don't need iPads or 3D television. In an era when the gramophone was newfangled, he simply wouldn't have conceived of such things. And it's highly likely that he was content with everything he had.
Brett Debritz is a freelance journalist based in Brisbane