The man to whom I gave a gentle push so that I might fit inside the crowded commuter train this morning was wearing an Apple Watch.

As the train stopped in a tunnel, the man apparently received a reminder on his wrist, and when he raised his wrist I got a clear view. No, it wasn’t one of the knockoffs they were selling at CES. This thing looked like a luxury item, and it had the now familiar “bubbles” Watch user interface.

I saw a text reminder on the screen, and then, briefly, a map. It appeared that the guy had been using the Watch for some time and was pretty used to it. The product is supposed to go on sale in April, but Apple gave Watches to a number of its employees to gather feedback and fix bugs.

On this guy, at least, the Watch looked proportionate to his wrist. The polished metal watch band looked very traditional, and, it seemed to me, made the Watch itself seem less out of the ordinary. It’s very much within the wristwatch paradigm, and doesn’t scream for attention.

One thing that disturbed me slightly about the device?

Like other blockbuster Apple products, when you see it, something somewhere in the corner of your mind clicks on, and then you realize:

You want one.

I want one, and I didn’t even really see much of what the thing could do. But I got the distinct impression that the Watch has already become integrated into the daily life of this user. I could see it as a powerful personal assistant that’s always just an arm’s lift away to help you make sense of the minutiae of daily life: the schedules and reminders and appointments and social media and everything else we all have to process every minute of every day.

And it will get worse. The Watch will launch with just a limited set of features, and at first, it will seem like merely a remote control for your phone. But later on the Watch will start to do more and more things — some of them completely independent of the phone. Next thing you know, you’ll see people using the Watch to buy coffee at Starbucks, or scan to get on the train, or check in for a flight, or produce one’s medical records at the doctor’s office.

Apple will, of course, nail the marketing of the Watch. We’ll see all sorts of images of cool people doing cool things with the cool device. The fashion industry will embrace it.

But the most compelling advertisement for the Watch will be the sight of real people using it to do practical things in real life.