The Doctor grew oddly cautious. It was always a strange moment when he let someone in. He could count on one hand the number of people who seriously knew about him since the time war - Rose, Jack, Martha, Donna. Each reacted differently, of course. It was always sort of hard to know just how a human would react to being told they weren't alone in the universe. Or, in Jack's case, that they weren't quite as unique as they'd thought.
"Well, they were sketches of the TARDIS, which is essentially my home," he started, feeling his way through as he went. "My home, my world, it was destroyed in the Time War." There, that was easy enough. Though, he hadn't yet broached the subject of species just yet.
"So, when I said I didn't have a home, truth is I don't. I travel in the TARDIS, but I can never go back there." even if it travels through time and space.