Geraldo Rivera still thinks this guy looks dangerous. The face that launched a thousand friendships. (EDUARDO MUNOZ/REUTERS)

“It is a sobering thought,” said Tom Lehrer, “that when Mozart was my age, he had been dead for two years.”

I always feel some variant of this when Mark Zuckerberg’s birthday rolls around. Mark Zuckerberg is 28 now. Just 28? Sure, in Internet years, that’s 60, but still.

It is enough to give you a serious quarterlife crisis. On the one hand, this is good news, because it implies I will live to 96. But even if I make it that long, I still will not be Mark Zuckerberg.

It’s not that I haven’t accomplished anything in my life so far. Yesterday, for instance, I had some lettuce stuck in my teeth, and I managed to get most of it out.

But the gap between me and Mark Zuckerberg is only widening. To take a random example, if I went up to 901 million people and asked them to share their data and pictures with me, they would say, “No,” and then they would probably call mall security. This is unlikely to change with the passage of the years.

It is not that we resent Mark Zuckerberg, exactly. He has given us a great gift. He is entitled to be worth some absurd amount like $18.7 billion. That’s, as they say, cool.

To date, he is the only guy who can wander around in a hooded sweatshirt and not alarm Geraldo Rivera. Like Bill Gates before him, Mark Zuckerberg is that intent-looking fellow whom you once passed in the computer lab and shrank away from because you were going off to do something Relevant and Hip, and now you rue that day.

Thank heavens for Aaron Sorkin, who portrayed him in “The Social Network” as that guy two stops to the left on the evolutionary scale whose idea of a good afternoon is to sit around making glottal stops. We have to have some consolation.

But we should be happy.

After all, Zuckerberg created the original service that updates you constantly on how frustratingly well your friends are doing and forces you to acknowledge their birthdays. This must be catnip to him. In fact, if it weren’t for Mark Zuckerberg, I wouldn’t know when anyone’s birthday was.

So, happy birthday, Mark Zuckerberg, Facebook Founder and CEO. Happy birthday, Mark Zuckerberg, the college dropout worth millions, who gives the lie to all the conventional wisdom about success that they pump into you at graduation. You don’t need to have a degree or wear a tie to work — apparently, ever.

Happy birthday, Mark Zuckerberg, who turned wishing a happy birthday to people you met once at a stranger’s party into a national institution! Thank you for making certain I never forget another birthday again, even though I do not remember who numerous of these people are or how exactly I came to know them! HAPPY BIRTHDAY CARLENE! HAVE A WONDERFUL TUESDAY! ENJOY THAT GENERIC THING IN YOUR AREA!

And you too, Mark Zuckerberg! You started it, after all.