Twenty years ago, we were all pretty sure the world was going to end on January 1, 2000—or, if not the world, then at least civilization.

It had something to do with how most computer programs used the last two digits to represent a four-digit year, and when the clock rolled over at the end of 1999, every computer would think it was 1900. When that happened, ATMs would stop working, the electrical grid would shut down, planes would fall out of the skies, and newborn babies would get hundred-year-old birth certificates.

We were legitimately freaked out. And why wouldn’t we be? TIME published an ominous cover story with extra exclamation points. President Bill Clinton said not-at-all-reassuring things about Y2K like, “This is not one of the summer movies where you can close your eyes during the scary parts.” CNN suggested that readers prepare for Y2K by stockpiling powdered milk, canned juices, and “comfort food.” (Note: Tech Armageddon is easier to take with carbs.) Apple produced this TV commercial, which still makes us want to hide under the bed:

But then New Year’s came and went. We all woke up with electricity. ATMs didn’t refuse to dispense cash. Planes remained in the air. The great catastrophic threat of our time turned out to be a colossal dud.

So what really happened with Y2K? Was humanity ever actually in danger? Was this tech’s Cuban Missile Crisis, or Mayan Doomsday Calendar? To find out the truth, we spoke to the people who witnessed it firsthand: those brave souls who toiled in the IT trenches, surrounded by other underslept programmers, probably while crouched nervously behind a ThinkPad 701 or Bondi Blue iMac.