I spent much of my free time last semester watching a friend's DVDs of New School Who, and a sampling of her Old School Who (Tom Baker era), while waiting for this season's Doctor Who to start in America. I avoided most spoilers, but not
Lizbee's meta post on the difference between the old-school Doctor and Nine/Ten. Basically, it boils down to the fact that the Doctor is
deeply emotionally scarrred by the destruction of Gallifrey and his role in it, and doesn't believe that he deserves a second chance--and because he doesn't think he deserves a second chance, can't quite make himself believe that others do, either, making him a much harder character, and more prone to manipulate and use others. Not always, but often enough to be a serious problem.
lizbee thinks Donna is good for the Doctor because she's not going to let him get away with that kind of thing, and is
far more proactive about that than either Rose or Martha were, and when combined with the fact that he's had a little more time to heal than he has since the first time we saw Nine, he's actually starting to go back to something closer to what he used to be like. Having now seen the first few episodes of this season, I think lizbee's got some good insights here (although her knowledge of Old School Who is far superior to mine, so I can't judge that portion of her argument).
This, then, combines with something else I'd been thinking about as I re-watched the DVDs, namely that awesomeness that is Human Nature/Family of Blood. In Human psychology at least, a little temporary amnesia or denial can actually be a good thing, because it gives the mind time to put distance between a traumatic event and process it subconsciously and heal without having to DEAL WITH IT consciously. Like any defense mechanism, it's good in the short term but can be destructive when taken too far. Let's apply this to the Doctor: he's already trying denial as a defense mechanism (not talking about the fact that HIS ENTIRE WORLD AND ALL ITS PEOPLE ARE GONE unless the world is coming to an end counts, I think--and just watch his face when he's avoiding talking about it). Let's also realize we're dealing with the fact that Time Lords live very long lives, and what would seem like a long time to engage a defense mechanism to us probably feels very short to them.
So here we have the Doctor, as a human, not consciously remembering his past but still dreaming it, which means his subconscious is still processing it. He's happy and content, which he hasn't been since before his people were destroyed, at least. He's living in a stratified, stable society ruled by tradition (as Gallifrey was) that still is about to go through a lot of changes (and he likes that sort of thing), so it's about the perfect environment for balancing homesickness for a world that no longer exists with, you know, the fact that he couldn't stand to actually live there when it did exist. He's got the beginnings of a family, so he wouldn't be alone. He's got a job he enjoys--no one pontificates as much as the Doctor does who doesn't like teaching, at least the idea of it. If he'd used the Chameleon Arch again after dealing with the Family of Blood, he would have had a human-span life with Joan, a quiet life. No great joys and triumphs ... but no great tragedies, either. Just the thing to let him heal a little.
Then all you have to do is have Martha look up his obituary in the papers and use the Tardis to go back in time to the day before. She gives him the pocket watch and he's the Doctor again, except one who's had a long time to lay quietly and rest. Run the obituary the next day, and off we go again. (The fact that I loved Joan and wanted to see more of her has nothing to do with this idea, nothing, I tell you. Or that I would love to see the Doctor try and extricate himself after several decades of a human life, and see him deal with those kids we saw in his vision, whether or not they were fully human or regenerated into Time Lords eventually.) I think that if HN/FoB had happened after the Master arc, the Doctor might have chosen something like this, or at least been more likely to.
I doubt I'll ever write this idea, but it's a fun one to contemplate. I have this scene where he's convinced some of his family to take a trip in the Tardis with him to the early 21st Century to drop Martha off (in my AU timeline for this, HN happens right after Last of the Time Lords, and she didn't say she wanted out until after HN/FoB). Anyway, so they're in London and he's buying cell phones so his human family can call him if they need him, and Jack Harkness comes up behind him and swings him into a kiss by way of a hello. And the Doctor's family, coming from the mid-20th century (maybe ca. 1950/1960, if we take the vision as a clue to when human!Doctor dies?) is SHOCKED, and the Doctor doesn't get why, and then he says something about how he just doesn't understand humans--they don't care that he spent forty years married to someone who wasn't even a member of his own
species, but snogging someone of the same gender throws them?!? This then requires him to introduce Jack to his family, which shocks Jack (Jack is so hard to shock that it amuses me to think up things that actually would).