WASHINGTON –

In television's vast universe, there is perhaps no acquired taste that is more difficult to acquire than the taste for "Doctor Who," BBC's long-running sci-fi series about an alien dandy who navigates the time-space continuum in a phone-booth-style British police box. It's been on (and off, and then on again) for five decades, but despite its increased popularity, "Doctor Who" remains steadfastly niche.

And before fans come at me with their sonic screwdrivers bared, let's assume that "acquired taste" is meant as the highest compliment in this full-blown nerd era. The show's remoteness — and the way it has skirted the edge of mainstream success for so long — remains its strongest asset.

From its earliest episodes, "Doctor Who" has rewarded a certain stripe of viewer who can pay close attention while cerebrally forgiving the show for its low-budget, slapdash, resolutely episodic qualities. It's melodrama for Mensa. One of the main reasons "Doctor Who" thrived, in fact, was because its fans came to love it as much for its shabbiness as its exuberance and manic intelligence. The bells and whistles of the CGI era have caught up to "Doctor Who" and made it infinitely cooler to watch since 2005, yet it's still appreciably outre.

And so, to a growing list of 50th anniversaries, we must add the Nov. 23, 1963, premiere of "Doctor Who," a television show that, if nothing else, tells us a lot about the nature of TV (and the sentimental devotion of fans) on both sides of the pond.

Even if you've never seen the show or long since concluded that it's not your cup of tea, there are several specials and retrospectives scheduled this week, offering ample opportunities for the casually curious to share in the anniversary mirth.

Though the circumstances of "Doctor Who's" shaky beginnings are well documented and firmly part of fanboy/fangirl lore, it would take another 50 years to read everything ever written about the show and watch old episodes.

Dipping into the archives, I found myself most drawn to a video compilation of every iteration of Ron Grainer and Delia Derbyshire's collaboration on the catchy theme music for the show, which harnessed the high-tech ideals and low-tech execution that became the show's stock in trade. The years go by and the synthesizers get more ridiculous and Moog-ish — up until the modern era, which turns the theme into something more serious, more appropriate, more stylized.

There you have the "Doctor Who" problem for those of us who could take it or leave it: The concept and feeling of the show (the music, the strangeness) seem so inviting at first, both as a story and as a worldview; but then, a couple of episodes in, "Doctor Who" still feels dauntingly remote and lacking in soul.

It comes down to trying to explain what kind of guy the Doctor is. It feels like all 50 years of the show have conspired to make sure we never know. Even his real name is never to be revealed.

The answer, obviously, is that he's not a guy at all. He's an alien — given to moodiness, wacky fits and bizarre non sequiturs. Each of the men who succeeded the original Doctor, William Hartnell, brought his own interpretation to the Doctor's quirks — as did the writers — but only recently, with David Tennant (who played the 10th Doctor from 2005 to 2010) and his successor Matt Smith (who will now hand the role over to Peter Capaldi), has the Doctor flowered as a more humanlike entity. I side with fans who spent the summer hoping, before Capaldi was chosen, that the Doctor would finally morph into a woman.

The show assiduously treats the Doctor as empathetic but essentially asexual and averse to romance; fans argue about this a lot, especially since both Tennant and Smith exuded high doses of charisma.

The Doctor certainly grew fond of the 50-year parade of comely women (and handsome men) who've traveled with him as seasons came and went. It can feel, after so much time spent with the Doctor, that one is also wasting too much time with the Doctor. He morphs and morphs but never really changes. Which means that even now, slicked-up and improved as it is, "Doctor Who" can still feel like a show designed to hold a place on the schedule.

Fans certainly don't see it that way. For them, the show has never been anything short of a marvel. It's also an old friend to American sci-fans of a certain age who remember (as I do) when our local PBS affiliates started importing "Doctor Who" reruns in the late 1970s and early '80s (during the Tom Baker years) along with reruns of "Monty Python's Flying Circus." With that unlikely pairing, a nerdy adolescent in, say, Oklahoma was exposed to a certain British sensibility; it was like discovering another planet, a place where you might belong.

In that same spirit, "Doctor Who" is still an occasionally terrific (and reliably comforting) show, no matter what season you're watching or on what continent. I envy the people who give the Doctor their unconditional love, even if he is incapable of returning it.

The 50th anniversary episode will be simulcast globally on BBC America. There is no word yet as to a Japanese broadcast.