The TARDIS Theory That Changes Everything On Doctor Who
"Doctor Who," the long running and beloved British series, is no stranger to shaking things up. Since its conception in 1963, there have been 13 incarnations of the titular Doctor, spanning nearly 900 episodes, with each bringing their own aesthetic and personality to the sci-fi drama. It's a clever storytelling gimmick because the changing of the guard provides guaranteed, cyclical novelty and a built-in justification for "Doctor Who" to continue churning out content until the literal end of time.
In Season 12's tenth and final episode, "The Timeless Children," it was revealed that The Doctor (played by Jodie Whittaker) was the Timeless Child, a being capable of regeneration and the genetic template for all Time Lords thereafter. This newest retcon came as a surprise not only to fans, but to the Doctor herself, as it was also revealed that Time Lords had their memories wiped after every 12th regeneration. In the same episode, we see a heretofore unknown incarnation of the Doctor piloting the TARDIS. It's a revelation that's inspired some intriguing theories among the show's dedicated fanbase.
What Does The TARDIS Remember?
As "Doctor Who" has already provided us with an origin story for how the Doctor came to own the TARDIS (i.e. he stole her — with her permission; a critical caveat that she made to sure voice when she took on a human form in Season 6's fourth episode, "The Doctor's Wife"), fans have resorted to filling in the gaps created by this new wrinkle themselves. In a simple yet compelling theory post, Redditor u/Lyoko01 suggested that the reason the TARDIS allowed The Doctor to steal her was because she remembered their time together from before the last memory wipe.
Redditor u/iatheia lends further evidence to this theory by adding a direct quote from the "The Doctor's Wife," in which Idris (the TARDIS' human name) claims to have archived roughly 30 versions of the control room (the hub that changes forms with The Doctor), a number which is far greater than the known number of incarnations of The Doctor thus far. The Doctor believes this information is in reference to versions of him that have yet to occur, but as u/iatheia notes, "one can read another interpretation into this."
It Doesn't Explain Everything
As fun and intriguing as u/Lyoko01's theory is, the idea isn't quite a perfect fit. Redditor u/AmberMetallicScorpion reminds us that the first incarnation of The Doctor (William Hartnell) stole the TARDIS, so at least, "The Doctor before the first didn't own the same one." Less helpfully but straight to the point, Redditor u/DarioMac108 stated in opposition that, "you can't rationalize poor writing."
While "Doctor Who" inarguably has rewritten its own history innumerable times (i.e. Peter Capaldi's portrayal of The Doctor was supposed to be the last iteration, according to the show's own lore), we'll leave any stances upon the quality of the writing up to you, dear reader. What we can say, however, is that the concept of The Doctor and the TARDIS being almost fated to share their journey through time together, over and over again, is one we're probably going to hold on to until proven false.