The news that Superman will be revealing his secret identity as Clark Kent to the world this month would be a lot more shocking if it hadn’t already happened four years ago.

But the fact that this is the second time demonstrates one thing that’s possible in comics that we haven’t mastered in the real world: putting the toothpaste back in the tube.

In a story written by Gene Luen Yang, Lois Lane told the world Kent was the Man of Steel to thwart the plans of a villain using the secret to blackmail him. The revelation turned the hero’s world upside down, but the new status quo was short-lived as he wound up dying due to Kryptonite poisoning.

The void was quickly filled by the Superman from the pre-New 52 continuity, who was already secretly living in and helping save the rebooted world. Eventually, the histories of the new and old Supermen were combined because… well… the short answer is the writers and editors wanted to do it.

So now only a handful of people know that Clark Kent is really Superman, but that’s all about to change in “Superman” (volume 5) #18, written by Brian Michael Bendis.

The secret identity bubble burst in the movie world in 2008, when Robert Downey Jr.’s Tony Stark copped to being Iron Man at the end of the character’s first film, rather than go with the true-to-the-comics cover story that Iron Man was his bodyguard. That fast-forwarded what happened in the comics, when Stark unmasked during a press conference to save a dog that was about to get hit by a stolen armored car in “Iron Man” (volume 3) #55.

The biggest Marvel identity cat left the bag in 2006, when Iron Man convinced Spider-Man to reveal to the world that he was Peter Parker in “Civil War.” It was part of Stark’s strategy to drum up support for the Superhuman Registration Act, the catalyst for the conflict.

When Parker switched sides, he had to go on the run. As he’d always feared, his public identity put his loved ones in danger, and an assassin’s bullet meant for him nearly took the life of his Aunt May. That led to one of the most controversial comic stories ever – one I’ve bemoaned in this space before – in which Spidey made a deal with the devil (well, a devil) to undo the damage in exchange for him and wife Mary Jane allowing their marriage to be erased.

Daredevil didn’t initially volunteer his identity, but former flame Karen Page sold it for drugs and the secret eventually made its way to the Kingpin. The villain used that information to dismantle Murdock’s life and later shared the secret with Mysterio, who was looking for another arch-foe to stand in for Spider-Man.

Under Bendis’ pen, a tabloid revealed that the blind attorney was also the red-costumed vigilante, something Murdock battled in public and in court. Iron Fist stood in for him for a while to provide some misdirection, but eventually Murdock admitted he was Daredevil – only to have the Purple Man’s mind-controlling kids make the world forget as a thank-you to the hero.

(Incidentally, Iron Man used a similar approach with the villain Mentallo’s technology to re-hide his identity before the aforementioned reveal that stuck.)

Wally West, who followed in uncle Barry Allen’s footsteps as the Flash, had a public identity for most of his career. But he enlisted the aid of former Green-Lantern-turned-Spectre Hal Jordan to mystically re-mask him following the apparent loss of his twin children (later saved through time travel).

Evan Bevins is the writer of the webcomic “Support Group.”