In 2013, Anthony Hopkins watched “Breaking Bad.” Soon after, the world — at least the internet — would never be the same.

Following his binge-watch, Hopkins wrote an effusive letter to Bryan Cranston, which went viral online. The story gained momentum again after being posted on Reddit Monday.

In the letter, which first made the rounds after a “Breaking Bad” cast member shared it on Facebook, Hopkins called Cranston’s portrayal of Walter White the “best acting” he’s seen. No argument here, dude.

Everyone rejoiced in Sir Anthony Hopkins’ words, except, of course, for Sir Anthony Hopkins, who told HuffPost in 2016 that he doesn’t write people letters anymore because of it.

“I just wrote this personal letter to Bryan,” Hopkins said. “I didn’t want it to be known publicly, but that’s what happens today. You can’t open your mouth before it goes on the internet or whatever you have, on Twitter or Facebook.”

“I keep my mouth shut from now on,” he added. “I don’t write letters to people.”

In an interview with HuffPost last year, Cranston responded to Hopkins’ disappointment and recalled how the letter ever got on the internet in the first place.

The anecdote didn’t make it into our previous story, but in light of the letter making rounds again, here’s the scoop.

“Well, I was amazed when I got the letter. I was astonished that Sir Anthony Hopkins himself wrote me a letter, and I was taken aback. I was tickled and honored and humbled, and it was quite a thing,” Cranston said.

The actor explained that he wanted to share the honor with his co-stars as well.

“I then proceeded to write a letter to my co-stars, [whom Hopkins] praised a lot,” Cranston said. “I started to write, ‘Anthony Hopkins wrote me a letter and he said basically,’ and I stopped and went, wait a minute. Why would I paraphrase him and capsulate what he wrote? I should just let them read the letter,” he explained.

Instead, Cranston sent an attachment of Hopkins letter to the cast along with a note: “Listen, here is what Anthony Hopkins wrote to us as a cast, and I thought you’d be as thrilled as I was. Enjoy it, Bryan.”

This is where things broke bad.

Someone in the cast, reportedly Steven Michael Quezada, shared the letter online, and it gained attention fast. Hopkins was obviously not pleased.

“In this new age, I didn’t anticipate someone posting that. I didn’t anticipate that someone would then take the letter and show it to the world. It was an oversight of mine, so when it happened I thought, ‘Aw crap.’” Cranston said. “I now have to realize that.”

As much as Hopkins learned not to write letters, Cranston said the moment taught him to be mindful of social media.

“With the advent of Twitter and everything it’s like, OK, so now anything you say on social media is for the world to see and it is forever,” he added. “So I got it. But at the time, I wasn’t in the practice of saying, ‘Please don’t share this on social media.’”

And that’s how a letter goes viral, people.

It’s too bad Cranston and Hopkins can’t enjoy their correspondence (which you can read here) as much as the rest of us. But who knew a few words about “Breaking Bad” would still be breaking the internet today?