As you’ve probably noticed if you’re on Facebook, the service has become ever-more aggressive about encouraging you to celebrate the birthdays of those in your social graph. It reminds you of your friends’ birthdays via notifications (“Wish them the best!”) and allows both those with a birthday and their friends to exchange sentiments via a special interface designed for efficient bulk celebration. It’s even experimented with pre-filling out birthday wishes, allowing you to thoughtfully mark a friend’s special day with a single click.

For years, I played along. This year, however, I marked my birth date as private, which shut down Facebook’s whole birthday ritual. The difference was surprising: I didn’t get a single socially networked greeting from the previous broad cross-section of well-wishers.

While this was the outcome I wanted, it still left me stunned at Facebook’s birthday hegemony. We may have outsourced our many happy returns to Mark Zuckerberg as part of his return on investment. (Though Facebook doesn’t directly monetize birthdays, anything it does to keep people engaged on its platform makes it a more powerful advertising medium.)

At the moment, this might seem like the least important complaint you could possibly lodge against the embattled Bay Area tech behemoth. But unless you’re quite young, think back just a few years and recall the relative privacy of your day of birth, with or without its year attached. It was something you could choose to share or not, and many people among my acquaintance didn’t. Some preferred to celebrate their birthday only with family or a…