While discussing space and astro-physics with my son, who turns six today:
Mammy: You can read some of the books on space when we get home.
C (6 y/o): I can't, Mammy. I'm too busy reading Alastair Reynolds*.
Mammy: Oh. What page are you on?
C: Page one! Hmmm... maybe two. Or three.
* For reference, he has picked up Pushing Ice from Alastair Reynolds, which is really not targeted at the 5-6 year olds.