Apple told us almost everything about the new Apple Watch at its event on Tuesday.
It told us how it took three years to design this beautiful new piece of hardware, how they shrunk down a touchscreen interface for a tiny screen and how they crafted its shell from sapphire, gold and aluminium.
It told us how it can send your heartbeat to your loved one, take and make calls, notify you when you get an email and tell the time on Earth and on the Moon. It told us about the health benefits and the music playing features, and the style options and the fashionable straps.
But the one thing it didn't tell us is the one thing we needed to know: what problem does an Apple Watch solve?
At the launch of each of its major new product categories in recent years, Apple has approached its keynotes like a GCSE essay. They have outlined a problem in clear, simple language, described some existing solutions and their flaws, and then given their answer to the problem.
The iPhone is the classic example. It was the best iPod you could own, the best way to browse the internet on the move, and the best phone you could buy.
The iPad? The best reading, watching and browsing device you could buy.
The Macbook Air? The lightest, thinnest laptop ever made.
The Apple TV? Airplay.
And to be fair, last night's Apple Pay? Credit cards suck, here's a replacement.
The odd thing about the Apple Watch is that Tim Cook didn't offer either the problem it solved, or the solution it presents.
Yes, he implied an overall sense of what it does, through explaining several key functions. But none of them can honestly - or were even pitched on stage - as genuinely better than the other existing solutions for those problems. And none was a killer, central, oh-right-that's-what-it-does headline feature that transcends how we already thought about the category.
The Watch is a health tracker, and a well-designed one, though it lacks GPS and any obvious way to connect to bike sensors or other higher-tech equipment. It's a way to check your notifications, but is it honestly better than your phone? It's a map, but with a tiny screen. It's a clock, but one you have to charge every night. It's a way to send messages, though not as easily as with your phone. And so on.
Ultimately, the Apple Watch doesn't do much that the Galaxy Gear 2 doesn't already do. It's a vastly better, more beautiful, more thoughtful, intuitive conceptual way to do those tasks. But the core functionality is just as diffuse, just as supplementary, and just as confusing as Samsung's early stab in the dark.
Which is not to say that the Apple Watch is actually a disappointment, on its own terms.
It's clearly a clever and thoughtful new way to think about a wrist-mounted wearable gadget.
The ultimate objective is to swap that brick in your pocket for a series of intelligent, small devices on your person. And it's customisable and stylish in a more complete way than most expected. If you're an early adopter, you might already be sod. It will look great on celebrities' wrists at the Oscars. You may very well want one but not know why.
Indeed, we would be stupid - or deliberately angling for a link on Daring Fireball in five years' time - if we were to claim that the Watch is destined for anything other than an interesting future, and one we can't yet (probably) foresee with accuracy.
But as for the event last night, it's also fair to say that the Apple Watch -- all smartwatches really -- still lack a definitive reason to exist.
Just try it. When you next move outside the tech or fashion bubble, and someone asks you why they should want one -- or rather "what does it do?" what will your answer be?
Ultimately, right now, it will be the same as Apple's pitch: it tracks stuff, shows stuff, does stuff, looks neat…
"No, what does it do?"
It has these features, and it can pay for things…
"Seriously, what does it do?"
We… don't know. So, does Apple?