"Gilded Youth" by Tom Quinn reveals Prince William and Kate Middleton's ordinary life behind palace doors.

The book explores how the traditional upbringing of the royal family has changed.

The couple fights and affectionately calls each other pet names like "babe" and "Babykins."

William is obsessed with Kate's hair, which she calls "baldy." He irritably calls her "darling."

Kate's "Buddhist calm" helps her navigate the traditions of the royal family.

The couple wants to represent historic continuity while also living an everyday life with stresses like work and children.

They break royal tradition to give their kids a normal childhood.

William was called "Wombat" by Princess Diana, a nickname he still uses.

Middleton's stoic demeanor has been essential to her success in navigating the traditions of the British royal family.