If ever a word deserved to be hung from a gibbet and flogged to death then buried in a concrete-sealed pit some 1000 meters deep, it’s intuitive. For some time now it has been slyly shifting its meaning from something that had value to a meaningless catch-all that’s lost any grip on reality.
The Oxford English Dictionary  gives us a reasonable and workable definition as follows:
a. Of knowledge or mental perception: That consists in immediate apprehension, without the intervention of any reasoning process.
b. Of a truth: Apprehended immediately or by intuition.
c. Of any faculty or gift: Not acquired by learning; innate.
The more recent definition that appears to have taken over is;
Requires no learning whatsoever.
This has, at least, the flavor of the OED’s “immediate apprehension” about it but it fails to consider the reality that in the real world, almost everything we know and do has to be learned. The amount of time it takes to learn something may vary, but we still have to learn it.
Which is where sitting on the toilet comes in.
If the closest you’ve ever come to visiting Germany is drinking Jäger-bombs at a pre-wedding Bacchanalia or singing along to the 80’s hit, 99 Luftballons,  you are extremely unlikely to have come across the word flachspüler. And before I define it, take a look at this picture:
Take a good look at the inside. Do you notice that there is a small hole at the front a shelf taking up much of the bowl? Now imagine – stay with me on this – you’re sitting on the toilet and engaging in some “evacuation.” Where does the stool end up? If you guessed “on the shelf,” then give yourself a round of applause.
So now, before you read on, on a scale of 1 to 10, where 10 is “brilliant” and 1 is “crazy,” rank how good an idea this shelf is. If you have never seen this sort of toilet before, how “intuitive” is the design?
Your evaluation of the “goodness-of-idea” will inevitably be based on previous learning and what you already know about the world and how it works. You know something about toilets but up until now, the aim has been to get the stool into the water as quickly as possible. The idea that you might want it to first sit on a shelf and then get flushed away has probably never crossed your mind.
Let me help your “intuition.”
The shelf is called a flachspüler. which comes from flach meaning “flat” and spülen meaning “to flush” or “to rinse.” So it’s literally a “flat flush.” The shelf performs two functions. The first is to prevent “backsplash,” the phenomenon whereby dropping a heavy load into a deep bowl can cause water to shoot up and provide an unintended botty-wash. The second is to allow for the inspection of the stool before it makes its merry way into the bowels of the sewage system.
Now you may find the notion of stool inspection rather bizarre, but when people are ill, collecting stool and urine samples is pretty standard practice when trying to determine a patient’s condition . In fact, who amongst us hasn’t taken a peek at our poop to check that it’s normal in color and consistency? Those of us who have kids will remember well how we would not just change a diaper but take a peek at the poop to make sure things are OK.
The point is that in order to understand the meaning of the word flachspüler you either have to have been born and raised in Germany or read this article. In the first instance, asking a German to label the flachspüler in a picture would be thought of as “intuitive,” but for anyone else, it would be fairly impossible. What’s intuitive for a German is not intuitive for the rest of us.
This doesn’t apply just to bathroom furniture. It applies to the simplest of things. Here’s an example for the tablet generation: If you want to see a different screen on your device, how do you do it? You swipe from one side to the other, obviously. But how “obvious” is that?
Prior to the introduction of touch screen technology, the idea of swiping a screen didn’t exists. It’s a mode of access that is relatively recent and is now taken as intuitive. It’s so ingrained that when I bought my wife a Kindle, she tried to turn the page by touching the screen – and she’d never owned a touchscreen device before! Her knowledge of how to use the display was based on learned assumptions.
You see, many things are only in obvious if we’ve some experience of them – or elements of them – from the past. When people use a check mark for yes and a cross for no on an AAC device, that’s not intuitive unless you’ve learned that these two symbols are used in our culture to represent those words. It’s an arbitrary convention. The same goes for an image of “thumbs up” or “thumbs down” for good and bad.
The question you should always ask when something is described as being “intuitive” is “What do I have to already know in order to do this?” You may be surprised at the amount of learning you’ve already had to go though in order to see this new thing as intuitive.
Donald Norman, in his very readable Living With Complexity (2011)  says that, “even activities that we like to call easy and ‘intuitive’ are actually complex, arbitrary, and difficult to master.” In the quest to make things instantly usable we are losing sight of something very, very critical; we still have to learn new things and these new things have to be taught. 
Whether you’re a parent, clinician, or teacher, you cannot be replaced by some magical intuitive system. Although there is no reason why we should not be designing systems to be easier to learn, we cannot forget that some learning will be necessary. We all want out lives to be simpler and easier, but sometimes there is no substitute from a little blood, toil, tears, and sweat .
 I recommend the Oxford English Dictionary (OED) as the primary source for all things etymological in English. My other recommendations are the New Oxford American Dictionary (NOAD), the Merriam-Webster Third International Dictionary, and the American Heritage Dictionary, 5th Edition. For online resources, the Merriam-Webster is cool, and for language learners, the Longman Dictionary of Contemporary English.
 It’s says something about the attitudes of folks in the US versus those in the UK that the 99 Luftballons was released in the UK in English whereas it stayed in its native German for the Americans. I’m not exactly sure what it says but it seems significant!
 The examination of faeces for the purpose of diagnosis or divination (yup, you can tell the future by looking at a turd) is called scatomancy. Scatology is the study of shit, with scat being Greek for dung. The suffix -mancy means “divination by,” hence tephromancy (divination by ashes), catoptromancy (divination by using a mirror), and austromancy (divination by observing the winds.)
 Norman, D. (2011). Living With Complexity. Cambridge, Mass.: MIT Press.
 Just before I posted this piece, a colleague from Germany sent me a link to an article in the online edition of The Atlantic that talks about how using a dial phone was, initially, a non-intuitive process, and how people had to be taught how to do it. The article also includes a link to a wonderfully nostalgic black and white film called Dial Comes To Town. Well worth the watch! There’s also a quote from the article that’s worth repeating; “We forget how much of our interactions with technology, however ‘intuitive,’ are learned behaviors. For many the idea of needing to learn how to use the thermostat, the stove, the phone, or even a new piece of software seems absurd. We expect things to work, without having to work ourselves.” Which is precisely the point also made by Donald Norman.
 Although this phrase is typically associated with Sir Winston Churchill’s address to the British people at the beginning of World War II, it was apparently first used by the Italian politician Giuseppe Garibaldi back in 1849. Garibaldi also gave his name to a red women’s blouse, a hat, a biscuit, a type of beard, and a fish!
i do not entirely agree. when i saw the picture of the toilet, I immediately understood the purpose of its design. however I have never been to Germany or seen one of these toilets before or even heard the word flachspüler. When given a computer back in the 1970’s at the age of 8 I also was immediately able to ‘intuit’ how to use it. Of course then learning is required to master it, but there was an initial intuitive understanding of what it should do and how to go about making it do it… Perhaps some people are just more able intuit than others. However the point you make about how there is much more going on in the brain than we are aware of, is very true. Research shows that six seconds prior to us making a decision, the subconscious mind has already made that decision, and this can be observed by MRI. and so, Someone watching the MRI computer screen can know six seconds before you do, whether or not your going to choose this or that.
You are, of course, right to “not entirely agree” because seeing as “intuition” is a human phenomenon it is subject to inter-subject variability. As you say, some folks may well be able to “intuit” something more quickly than others. In his book “Thinking, Fast and Slow,” behavioral economist Daniel Kahneman distinguishes between two systems of analysis: System 1 (Thinking Fast) is unconscious, intuitive and effort-free; System 2 (Thinking Slow) is conscious, uses deductive reasoning and requires you to do an awful lot of work. The point is that System 1 is only “intuitive” because it uses heuristics based on years of previous experience. In other words, intuition is learned.
I guess what we want folks just to bear in mind is that whenever someone promotes a product or service as being “intuitive” you should step back for a second and pop on your Skeptik’s Hat and take a few minutes to work out what that really means? Sadly, many folks see the word “intuitive” as simply a good marketing word, along with “free,” “new” and “game-changing.”