“The appeal of Doctor Who is that you can do anything, any when, you can have him meet anyone,” Handcock said. “That's irresistible as a writer. You're given a completely blank slate, but you're given one of the best characters ever devised in fiction to have an adventure there. You present someone with those two factors, and they're going to leap at it.”

And Doctor Who is uplifting. As dark as the show can get, and as high as the body count can rise (which is very high), there's always a sense of joy and discovery there. The Doctor can be manipulative and brooding, but he's always been an explorer first. The show is about saving people and helping others, not getting revenge or hurting someone, and its unabashed love of seeing new things and the best in people makes it fun. In a musical number on The Late Late Show, Craig Ferguson summed up Doctor Who’s charm: “It's all about the triumph of intellect and romance over brute force and cynicism.”

“I watch what they do and think 'that's wonderful!' There's this crazy mishmash of ideas and at the core, there's still this idea of humanity,” Jahchan said.

That combination of optimism and no-boundaries storytelling options has allowed the show to continue to this day. The fans kept the show alive for seven years between the end of the original series and the television movie, and nine more years until the show got a full restart. When the BBC brought the show back in 2005, there was not only an existing fan base, but people of all ages who had at least some knowledge of the show. And this time, it had the support of the studio, and not its disdain.

Some of the fans who had kept the show going, from original revival showrunner Russell T. Davies to writers such as Paul Cornell and Robert Shearman, also found themselves in major positions to run the revival.

“What was smart about the reboot was that it was all fans of the show,” said Maura Grady, a Doctor Who fan and an assistant professor at Ashland University who focuses on fan culture. “They weren't hired because they were fans, but they came into writing and directing through Doctor Who, so they had this big wealth of knowledge to tap into, but not in a way that's off putting.”

“If you look at the Doctor Who stories, be them the show, the books, the audios, every single person that writes one of them, you can see that they're fans,” Lee said.

And with the big relaunch, the show has also benefited from a whole new audience: North America. The Internet and changes in cable programming meant it was no longer only available in limited public broadcast networks or hard-to-find recordings.

“It's easier to watch it now,” Miller said. “Doctor Who was difficult to watch in the United States before. It was basically being shuttled off to the PBS's of the world. It eventually got to the US via SyFy, but that was on a year-long delay. From the new series premiere in 2005 to today, we've gone from literally waiting a year to watch new episodes to basically livestream of new episodes. Something is only popular if you can watch it, and that's something that people are figuring out.”