She refers to him as "her thief." The TARDIS was amazing as a human using her temporary voice to tell him what he means to her. She was smart and brilliant: "I wanted to see the universe so I stole a Time Lord and ran away.
What if every book you have ever read was really just blank, but filled with Psychic Paper. and you were reading only what you wanted to? WHOA THERE>>>>then why do my favorite characters die or the book takes a stupid turn<<<<