I’m hardly the first person to rant about this, but I have to say it’s one of the things that bugs me most about the on-screen revival of the Doctor: he’s constantly lying about his age.  Oh, sure, you can hide behind the old saw that he really has no clue – what with all his traipsing through time and space, I’ve no doubt that he’s lost track exactly – but that’s really no excuse.

Think on this.  There have been nearly a dozen occasions when the Doctor specified his age (I’m only considering televised episodes here – no spin-off media, since those bring in a whole extra level of complexity and continuity issues).  My research indicates he gave his age in the following episodes with the numbers indicated:

Tomb of the Cybermen:  450
Mind of Evil:  “several thousand years”
DW and the Silurians and Planet of the Spiders:  748
Brain of Morbius and Seeds of Death:  749
Robots of Death:  750
Key to Time (Ribos Operation):  756 759
Revelation of the Daleks and Trial of a Timelord:  “900, more or less”
Time and the Rani:  953

Two of these situations in particular lead me to believe the Time Lords, at least, had ways of keeping track of such things.  For starters, Romana has his exact age (759) on the tip of her tongue when the question of whether or not the Doctor is “old” is raised at the beginning of The Ribos Operation.  He corrects her (“756!”), but she claims he’s “lost count somewhere,” suggesting his age (or date of birth, even) is part of the “confidential” information to which Romana seems privy (what with details of his Academy record also blithely cascading forth).

My second piece of evidence along these lines is that in his first adventure in his new incarnation, Seven uses his age – 953 – as the door code to the Rani’s lab (it’s supposed to be her age, too; maybe it’s something about those Academy records after all…).  At this stage, he’s clearly still got an accurate count – at least by some calendar – on his age, since otherwise the number the Rani used would not have matched.  Somewhere within the next two incarnations, something happens to change that.

Maybe it’s something to do with the Last Great Time War (though that seems a bit melodramatic); the loss of his home planet has completely thrown off the Doctor’s sense of the relative passage of time.  That at least fits with the idea that other Time Lords knew how old he was – it might have taken their presence to keep him grounded (or honest, depending on how you see it).  Or maybe it’s some unknown timey-wimey adventure that regressed his physical age by a couple hundred years, and he’s decided that should count toward his overall stated age.  Frankly, any fan can come up with some vaguely plausible explanation to suit her or his own views on canon.

Personally, I think it’s just the Time Lord equivalent of “39 and holding.”  When he spouted off to Rose about “900 years of time and space,” I think he was talking about the time since he’d first stolen the TARDIS.  When she called him on it, he panicked – or, thinking that there was no one left to disabuse her of the notion, decided quite deliberately that there was no harm in claiming it as his age.

From that point on, it’s a bit of a different story.  In order not to be caught in a lie, especially now that he’s gotten in the practice of popping back and having his various Companions meet each other, I believe he made a conscious decision to start trying to be consistent.  I’m sure he doesn’t want his friends comparing notes and finding any more inconsistencies than they already do.  So once he gave the lie to Rose, he’s decided to “play it straight” for a while and stick with the spurious personal timeline he gave her.

For those who know he gladly told an earlier Companion he was half a century beyond that age two regenerations before, it’s irksome.  It’d be nice if he’d fess up that he shaved off a couple of centuries in there somewhere, even if he doesn’t know precisely how old he really is.  He could call it a “new age for a new Age,” or some such rot.  I suppose we’ll just have to be satisfied that he’s trying to be self-consistent with what he’s been telling people since the LGTW, since we all know how likely it is that the Doctor will ever admit to that kind of prevarication.

After all, as Four once said, “there’s no point in being grown up if you can’t be childish sometimes!”