Mostly I just want to post this picture again:
David Tennant reportedly loved Doctor Who from the age of three. In 1974, the Doctor’s main companion was journalist Sarah Jane Smith. Tennant might not remember her clearly from that time – though he might, he was five before she left the show – but as a dedicated fan he certainly would have grown to adore her in any case.
I’m sure there are quotes and comments somewhere, but for now just imagine: You’ve taken on the role of your childhood hero, and now you get to meet your heroine.