- Aliens
- Time travel
- Spaceships
- What my job really involves
- Where I've really been
- UNIT
- How much of my stories are actually true
- My mother
- My step-brother
- Most of my family, really
- The Doctor
- What I did when I was in MI5
- Any previous girlfriends
- School
- Most things from my childhood really
...It might have been simpler to ask what I do talk about. It probably would have been a shorter list.