Born in ’79, right on the divide between Gen X and Gen Y, I’ve spent a fair amount of time considering the differences between the two.

One area I’ve noticed in which the two generations diverge is their desire to own stuff, rather than simply have access to it. Gen X’ers went from collecting tapes, to collecting DVDs, to collecting MP3s; like me, many I know have giant iTunes collections. Gen Y, instead, is on Rdio, Spotify and Pandora en masse, uninterested in owning any music given that they have access to all of it. Or consider car ownership – something many of my Gen X friends willingly suffer through here in NYC, but which seems nearly inconceivable to my Gen Y friends, given Zipcar, Uber and Lyft.

In the office, I’ve noticed the same thing play out in the way the two groups manage documents. The paradigm of Microsoft Word (as well as Pages and its other desktop substitutes) is one of owning docs. I make a document on my computer. I send you a copy of the doc. You make changes to that document, tracking them perhaps, then send another copy back. We can loop around endlessly, each time creating new documents, each time owning the unchanged originals on our own hard drives. But nearly all the Gen Y’ers I know vastly prefer collaborating via Google Docs. There, though I may have created a doc, I don’t actually own it; in the act of sharing and co-editing it, the document itself changes. The Gen Y’ers see this as the very point: why keep out-of-date copies at all, unsure whether the one you’re looking at reflects the most current collective thinking? Whereas Gen X’ers seem vaguely anxious about the process, unmoored without an immutable earlier version in their possession.

Going forward, apps and platforms in a slew of areas seem to be puzzling through the own vs share question. Take your photos, for example, which you might want to back up in your desktop photo library and then back up further in turn to Dropbox or Picturelife; or you might be fine tossing them directly into Facebook albums, straight from your mobile device, without a saved copy anywhere outside the social network cloud. A lot of entrepreneurs and investors are placing bets on both sides. And, in that calculus, they probably need to think more carefully about the market demographic they’re hoping to target. Because, for the balance of their respective lives, I suspect Gen X and older will think about owning in one way, and Gen Y and younger will think about sharing in another.

A bit more than a year ago, I recommended Mailbox as the best iPhone email app. But while many of my younger colleagues use their phones as their primary email devices, I send nearly all of my emails from my Mac. So I’ve used Mailbox mainly for triage, and less for actual communications.

Last week, Mailbox started rolling out a beta of their OS X desktop app. Like the sadly defunct Sparrow, it’s minimalist in style, and blazingly fast. It also lines up well with how I use email – an emphasis on reaching ‘inbox zero’, and on archiving / searching rather than filing.

Like the mobile app, Mailbox on desktop allows you to ‘snooze’ messages, pushing them out of your inbox to reappear at a time you can actually reply to or act on them. And like the mobile app, Mailbox on desktop badges the total number of messages in your inbox, not just those unread.

I’ve previously found that changing email apps changes my emailing behavior. Using OS X’s built-in Mail.app, for example, causes me to let email backlogs pile up far more than checking the same email directly in Gmail. And, for reasons I’m still not entirely clear on, Mailbox is, in turn, even more effective for me than the Gmail site for staying on top of my inbox.

On the chance it works equally well for you, go check out Mailbox on OS X.

(A final note: as Mailbox is currently rolling out their beta, you’ll need to sign up to receive a ‘betacoin’ to activate the app. I have a handful of betacoins, so ping me if you’d like one.)

Douglas Adams once observed that, as we age, we start thinking differently about new technologies:

"Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works. Anything that’s invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it. Anything invented after you’re thirty-five is against the natural order of things.”

I thought of that quote recently, when Google acquired Twitch for more than a billion dollars.

You may have missed the news. Probably because you, like pretty much everyone I’ve talked with over the age of 30, has never even heard of Twitch.

So, allow me to explain: Twitch is a site where you can watch other people play video games.

That’s right. It’s a website where you watch video of the player’s screen, sometimes with a picture-in-picture video of the person’s face, too, while they play a video game. You don’t play; you just watch them do it. And, somehow, Tweens are on the site watching for hours at a time. Enough so that Google deemed it a billion dollars of eyeballs worth.

To me, however, it seems patently absurd. A sure sign I’m now over the hill, and losing my sense of tech cool.

I had a similar feeling this week, when I ran into a young guy I had wanted to hire as a designer for one of our portfolio companies. I had emailed him previously, and hadn’t heard back. I had Facebook messaged him, too, thinking perhaps he didn’t use email much. Nothing.

Oh, he told me when we met. He didn’t really use Facebook or email. Mostly he just communicated with his friends via Snapchat, and two or three other apps I’d never even heard of.

Ever precocious, I’m a year ahead on Adams’ 35-year cutoff for becoming a technologically-confused old man. It seems I have nothing to look forward to now but decades and decades of all my appliances perpetually flashing 12:00.