The Doctor nodded slowly, trying to think of the best way to describe it. "Yeah. I notice a dramatic difference between now and the very first, but then it's hard to tell if that's just age of the regeneration," he commented. "Romana... I used to know this Time Lady called Romana... she started off as someone I couldn't stand to be around, and then in just one regeneration she became my best friend," he tried to explain.
"It's... horrible when it's the other way around, though. Worse than a friend dying, because they're right there but... they're just not," he said, his brow pulling into a look of slight worry... but it was gone as soon as he started to talk again. "The basics stay the same, though. We had a lot of philosophical discussions about it. And when I say 'we', I mean me and about five people, probably," he laughed.
"Fortunately, I just seem to get more and more fantastic every time!" he teased, giving her a wink.