The Doctor Who Theory That Would Change Mary Poppins Forever
The Doctor in "Doctor Who" has always shown some very special — even magical — qualities, ever since his introduction to a British audience by the BBC in 1963. He (or she) is known to be a renegade Time Lord, who stole his ship the TARDIS (which stands for Time and Relative Dimension in Space) from his fellow time travelers to meddle with historical (and future) events and occasionally save the planet Earth. He has a soft spot for humankind, declaring numerous times — in different incarnations and episodes — that he is a guardian and protector of the residents of Earth.
In many ways, The Doctor is an idealized representation of a specific type of British hero — extremely knowledgeable about many aspects of the world, and somewhat separate and above humanity, while still being fond of human pastimes and friends. Among the tools that make the Doctor such an effective champion are the use of Gallifreyan technology, like his bigger-on-the-inside TARDIS and his sonic screwdriver, both of which he carries to help him in his adventures. However, he also has a quirky personality and brilliant mind, which assist him in his fantastical — but generally kid-friendly — travels.
Does this sound like any another English character you know ... maybe one from a popular Disney musical? If so, you might subscribe to one particular fan-based theory that's been making the rounds of the "Doctor Who" fandom for years.
Could Mary Poppins be a Time Lord?
This theory posits that Julie Andrews' Mary Poppins (who is "practically perfect in every way") has the same origin as the Doctor (who was "absolutely fantastic"). They are both Time Lords from the planet Gallifrey, not subject to regular rules of time and space. A Reddit post from nine years ago lays out some of the evidence, pointing out that both of these somewhat egotistical characters (in certain incarnations) have a certain affinity for hats. And they use similar technology: Mary Poppins' carpetbag is also bigger inside than out, and her umbrella doubles as a flying and traveling device of some kind. The theory's originator, u/SiliconLemming, also pointed out, "They feel compelled to help others without reward, and then leave once the issue is resolved. They will often leave without telling their newfound friends they are going."
More evidence comes from the fact that some incarnations of the Doctor and the Master, the only two known surviving Time Lords, have preferred the type of Victorian-style clothing that Mary Poppins wears (think first Doctor William Hartnell and Michelle Gomez's Missy). A more recent Reddit theorist, u/Thescottish_bendyfan, pointed out that Mary Poppins also wears some accessories associated with Doctor Who: the aforementioned umbrella, a red bow tie, and a scarf.
Also, both the Doctor and Mary can communicate with animals and small children. The Doctor did it with a cat in "The Lodger" and seemed to know baby Stormageddon's mind in "Closing Time," while Mary Poppins did it with the dog, Andrew.
The theory has some good explanations for Mary Poppins' magic
This theory notes that Bert (Dick Van Dyke) was likely one of Mary Poppins' former companions, as he has clearly gone on adventures with her in the past. And it points to an image, posted to Tumbler in 2012, which is purportedly from Google Maps. It shows a character dressed like Mary Poppins in Cardiff, where much of the rebooted "Doctor Who" is filmed and sometimes set — early episodes of the new series established that the TARDIS could refuel at the Rift, and it's where shadowy organization Torchwood is located.
Fans on the Tardis Data Core "Doctor Who" Wiki point to the fact that as of the Second Doctor's run, the fictional world is real — as are are pocket dimensions, as of the 11th Doctor's run. Either of these could explain how Mary Poppins jumps into Bert's paintings on the sidewalk.
And there's another parallel. In the Disney film, fans first meet Mary Poppins sitting on a cloud while doing her makeup. The 12th Doctor (Matt Smith), in "The Snowmen" holiday special from 2012 with Jenna Coleman, also sits his TARDIS on a cloud. Of course, as pointed out by u/The_Match_Maker on another thread, Mary Poppins would probably call herself a Time Lady. "Mary Poppins is nothing if not precise," the user said.
It's more likely that Doctor Who was inspired by Mary Poppins, than the other way around
Of course, other far-out, in-universe ideas have been proposed to explain the similarities. Mary Poppins could even be a version of the Doctor — or any number of regenerating beings that have been introduced in "Doctor Who" over the years, from River Song (Alex Kingston) and Jenny (Georgia Tennant née Moffett) to Romana (Mary Tamm and Lalla Ward) or the Rani (Kate O'Mara). She could be, as u/Impromark theorized, a version of Missy as written up for children by "Mary Poppins"' original author, Pamela Lyndon Travers. Or, heck, she could even be a regeneration of Maria from "The Sound of Music." It sounds just as possible as anything else!
In reality, Disney's "Mary Poppins," based on Travers' 1934 book, was released in 1964 — just a year after "Doctor Who" debuted. Time Lords weren't introduced into canon until 1969's episode "The War Games." So, it's more likely that "Mary Poppins" influenced "Doctor Who" than the other way around.
This does seem to have happened, actually. The Doctor Who Wiki reports that stage directions for the episode "Deep Breath" indicates Missy's dress was directly inspired by Mary Poppins. In 2020, Wired did a Twitter Q and A with current Doctor Jodie Whittaker, asking this: "So Merry [sic] Poppins is a time lord right?"
Whittaker's response? "Ooh. Ooh. Hmm. So I'm not the first female. That's just pulled the rug, hasn't it?" So now we know the truth ... maybe.