Rose immediately pulled close to him, feeling a bit clingy. She really didn't want to be away from him for a second.
"Will I be smarter? Suddenly know a bunch of advanced maths? Will I be able to speak Gallifreyan? Will I read really fast?" She was already overwhelmed, but leaning on him helped.
She was glad he was slowing down for her and letting her ask all these questions. Normally she would just dive along with him, not knowing anything. That was part of what he loved about her, she knew.
This was big, though. Really big. And she knew it wouldn't always be happy. There were things that haunted the Doctor, and she wasn't naive enough to think she'd avoid all of the darker corners of the universe. This wasn't something she could follow him blindly into; She had to make a choice. Otherwise, the first time something heartbreaking happened, the Doctor would blame himself for pushing her into it.