We’re a little over two weeks in the Christmas season, and I’ve already done it three times. Maybe you have, too. To me, it’s the first sign of the coming holiday, usually done while putting up the tree. And then again while baking cookies and/or wrapping gifts. I can repeat it from memory; its soundtrack takes me back to my childhood. And it was the way I memorized my first extended passage of Scripture.

Have you figured it out yet?

I’m talking about A Charlie Brown Christmas, of course! The holiday classic premiered on this day back in 1965 and has a been a staple of seasonal viewing for countless children every year since. For my family, it’s the show that kicks off our Christmas season and one we re-visit several times throughout the month of December. There is something so pure about this particular program, something that goes beyond the music, the animation, and the storyline.

Something network executives, at the time of its concept, were sure would never succeed. Citing everything from the score (believing jazz did not belong on television) to the inexperienced child actors (whose elevated vocabulary was “off-putting”) to the slow-paced story, the bigwigs at CBS felt sure the program was to a be a flop and certainly one to never run again. Even some members of Charles Schulz’s own team felt that way, too.

The only one who didn’t, however, was Schulz. And, interestingly, he wasn’t even the one who had the idea for the program in the first place.

A Charlie Brown Christmas was originally born out of a failed documentary by Lee Mendelson about Schultz’s life. Though the doc never sold, it did lead to the Peanuts gang being featured on the cover of Time magazine which, in turn, caught the attention of Coca-Cola’s ad agency, McCann Erickson. Holiday specials were all the rage, and an executive approached Mendelson about the possibility of doing a Charlie Brown-themed Christmas program. Mendelson, desperate for a win after his failed documentary, agreed and sold the program…all before even talking to Schulz.

In a 2015 documentary called The Making of A Charlie Brown Christmas, Mendelson remembered calling Schulz up and telling him they’d sold A Charlie Brown Christmas. “Schulz said, ‘What’s that?’” Mendelson recalls. “And I said, ‘It’s something you’re going to write tomorrow.’”

Soon afterwards, Schulz and Mendelson hired Bill Melendez, who had helped animate a two-minute segment in the never-aired documentary, to work on animation, and the three men huddled together Schulz’s office in Sebastopol, California to brainstorm story ideas. Mendelson had just read Hans Christian Andersen’s The Fir-Tree and suggested a storyline around a tree as sad and misunderstood as Charlie Brown himself. Schulz pitched the idea of a troubled and mis-guided Christmas pageant. Working together, the men created an outline and set out to work bringing the story to life.

Network executives began pushing back almost from the very beginning. The story was too slow. The voice actors too unpolished. And, when they heard the soundtrack from up-and-coming jazz artist Vince Guaraldi, they complained the tone was too somber and adult for a children’s special.

All the while, however, Schulz refused to budge on his vision, either for studio honchos or his own team. When Mendelson suggested a laugh track to help lighten the mood, it’s said that Schulz stood and walked out of the room. When Schulz, a Sunday school teacher, said Linus should recite from the Gospel of Luke, Mendelson and Melendez “looked at each other and said, ‘Well, there goes our careers right down the drain,’” Mendelson said during the documentary. “Nobody had ever animated anything from the Bible before, and we knew it probably wouldn’t work. We were flabbergasted by it.” Schulz, however, insisted the passage remain. The only caveat to which he did acquiesce? Changing the introduction song, when the Peanuts gang are seen skating on the frozen lake, to the now classic “ChristmasTime is Here,” a song Mendelson penned on an envelope at his kitchen table and for which Guaraldi enlisted the help of the St. Paul’s Episcopal Church’s of San Rafael, California’s children’s choir.

When the finished product was submitted after six short months, “the general reaction was one of disappointment — that it didn’t really translate as well as we thought it would,” former CBS executive Fred Silverman said in the 2015 documentary. The only thing that saved it from extinction was the all-mighty dollar; Coca-Cola had already paid for it and CBS had already bankrolled its advertisement and placement in TV Guide. Executives decided to follow through just this once, then bury the program, never to show it again.

But when A Charlie Brown Christmas aired at 7 p.m. on December 9, 1965 almost half of all American television sets tuned in. And, rather than “disappointment,” children–and adults–were thrilled. The reviews were outstanding. Washington Post TV critic Lawrence Laurent wrote, “Good old Charlie Brown, a natural born loser … finally turned up a winner.”

CBS immediately ordered four more specials; in fact, Schulz, Mendelson, and Melendez wound up making approximately 50 different “Peanuts” programs over the years, most of them for CBS. The Christmas special won both a Peabody and an Emmy Award; it has been shown at least once every holiday season since then. Everyone was completely and utterly surprised by its success.

Everyone, that is, except Schulz. As creator of the Peanuts gang, Schulz knew his characters best, but he also understood people. The universal theme of loneliness, rejection, and the perseverance in the face of obstacles is just as true today as it was 50 years ago. Most of all, however, it is the truth behind the Christmas season that rings out the loudest in this special, making it unique and perhaps one of the most beloved in an over-saturated market.

Even Mendelson, who initially fought against the inclusion of Scripture in the program, eventually admitted his error: “That 10-year-old kid who recited that speech from the Bible,” he concedes, “was as good as any scene from Hamlet.”

Merry Christmas, Charlie Brown.

And Merry Christmas to you, too.