The Tao of Doctor Who
I guess I should be up front and make clear that I'm not an expert in Buddhism or Tao. Nor am I an expert in Doctor Who. And while I'm a big fan of Neil Gaiman's Sandman, I've not memorized the graphic novels (though I do have a print of the Endless on my wall). There's a few spoilerish elements if you've not seen seasons 1-3 of the reboot of Doctor Who. (I've watched a lot more since I wrote this, but it still applies, even though my examples only go through Tennant.)
There's something to be learned from them. Something about detachment - and dealing with the crap the Universe slings your way. It's easy (and common for Westerners) to hear a Buddhist or Taoist say "detachment" and translate that into not caring. I think that's an artifact of our language, though. We simply don't have the words to accurately express it.
It's like "I'm sorry." We say "I'm sorry" when something crappy happens to another person, and they reply "It's not your fault." It's a problem with the language. We don't really have a term in English like lo siento, and the translations ("I feel your pain" or "I empathize") sound pretentious. So we're largely stuck with "I'm sorry".
The same goes with "detachment". We commonly imagine a Spock-like impartiality, or an emotional distance like Doctor Manhattan in Watchmen. [LINK] But that's a Western notion, and doesn't really get the point across. So the other alternative - being entangled in the world, being entangled in meaningless obligations and social niceties 1 - leads us to Destruction.
I don't just mean in a metaphorical sense, but also to the character Destruction from Sandman. The embodiment of Destruction just up and leaves because he can't deal with the damage any more. He understands it intellectually - the old must go to make room for the new - but he just can't bear to see it anymore. But I don't think it's just a matter of caring. He was entangled in the world, so every turn, every change, every small bit of destruction hurt. It hurt to the point where he had to leave everything in order to escape the pain.
But then... then there's the Doctor. This Time Lord is in a similar emotional situation. He knows, from personal experience, that everything - EVERYTHING - goes away. Everything leaves. Everything changes. He's outlasted most everything and everyone he knows. And he still cares. He doesn't always care in the way people want, whether we're talking about Rose Tyler or Sarah Jane or Cpt. Harkness or Martha Jones, all of whom wanted the Doctor to be primarily focused on them. They claimed to care - or love - the Doctor, and I really think he loved them all back. But it was totally different.
See, that's the thing about "love" - another single word that is used in so many different (and contradictory) ways. "Love" is used to describe a relationship where one person completely subsumes themselves in the other (or both become a group identity as a "couple"). It is used to describe selfish, possessive desire (see: Twilight, Fatal Attraction) as well as the most selfless and painful of separations for the good of either (or both) partners (see: Martha Jones leaving the Doctor). One type of love - the Fatal Attraction kind - is all about entanglement. "I need you" and "I want you" are key phrases; possession remains a theme. It's a dark, seductive, visceral thing... and it's destructive as all hell. The other type is harder to recognize or describe, except as a negative. It's not need. It's not want, or possession. But it is about caring, and it is about wanting the best for other people, and it is about enjoying the time you have.
Back to the Doctor. When the Doctor is focused on you, he is completely focused on you. But at the same time, when you're not the primary focus, his mind moves completely on. 2 He mourns lost friends and lost companions - and then moves on. When you're about a millenia old, have seen genocide after genocide, saved the world and failed to save lives, the transitory nature of everything probably starts to sink in. So enjoy what's there in front of you. Have fun with it. Care about the people who are there, and relish that instead of missing those who are gone. Treasure your memories of happiness, rather than using them to poison the experiences you're having.
Sure, he's not entirely successful at this. Sometimes he wanders into the realm of being a little too detached, sometimes he's not detached enough. Just goes to show that we've all got to practice at it.
1 Key word: Meaningless
2 Mickey Smith couldn't deal with this for the longest time - until he built up his own self-esteem on a parallel Earth. His interactions with the Doctor in the Attack of the Cybermen are very different than the self-doubting, pratfalling Mickey of earlier episodes. I think this is a telling detail.