Microsoft/YouTube Screenshot by Chris Matyszczyk/CNET

When you want to know what's cool, you ask a teenager.

You have to ask her nicely or she will scowl you into oblivion or patronize you into a painful purgatory.

So I'd like to prepare you for some of this difficulty.

Teens have decided that Apple is, like, so over. If you want to be a veritable cooleratus, you want to be seen with a Samsung Galaxy phone in your hand or a Microsoft Surface laptoppy tablet stuck under your arm.

This definitive information comes to me courtesy of research performed by Buzz Marketing, as well as three 14-year-olds who tried to rob me of my orange Puma sneakers.

When they saw I had an iPhone, they couldn't even be bothered to take the sneakers. (I exaggerate slightly about this last element.)

As Forbes reports it, one of the sources of this deep technical disturbance is the self-obsession of those older people known as parents.

They have allegedly tended to toss older Apple products at their children, while buying themselves the latest iPhones.

Inevitably, this has caused a touch of pouty resentment among their offspring, who are forced to explain to their friends that possession of a smaller screen is not in any way their own fault.

Buzz Marketing's Tina Wells told Forbes: "Teens are telling us Apple is done. Apple has done a great job of embracing Gen X and older (Millennials), but I don't think they are connecting with Millennial kids."

This will surely explain why Microsoft had large numbers of Glee-ful teens dancing away in the launch ad for the Surface.

It may not explain so well why the Surface hasn't yet sold in limitless numbers.

Still, it's Apple's greatest challenge to maintain cachet as its products appear in so many more hands of so many more vintages.

When your logo gets seen too often, it can become a symbol of the establishment, rather than the renegade that teens are often desperate to embrace.

Teens want to believe that they have the inside track and that everyone else is worth nothing more than a snort. Why, they'll even allegedly drug their parents' milkshakes in order to get online.

They have great faith in their ability to unearth the novel and decry the status quo. The iPhone 5 was, for them, a little too staid.

As, it transpired this week, is Facebook.

But, as they learn only a little later, their feelings can't be trusted. Their greatest emotional stability lies in its fickleness.

Which, of course, ought to give hope to brands that haven't been in teens' minds for a long time.

I'm thinking of you, Nokia.