Mabel's inspiration for Rules for A Successful Life as an Undercover Secret Agent came from her parents' copy of The Moscow Rules.
The Moscow Rules are real. Well, maybe. At least lots of people think they are real. If you're interested in learning more about them, the International Spy Museum in Washington, D.C. posts The Moscow Rules online: http://www.spymuseum.org/exhibition-experiences/online-exhibits/argo-exposed/moscow-rules
I don't remember when I first learned about The Moscow Rules. In a childhood spent reading obsessively, I picked up lots of useless but fun information, like the fact that Thomas Jefferson had no middle name.
Mabel's Rule Number 23: Float like a butterfly, sting like a bee is a quotation from Muhammad Ali, the Greatest of All Time.
The expression "odd sock" came from the ABC TV show Castle. The ruggedly handsome Nathan Fillion (he'll always be my captain!) played the titular character Richard Castle, a mystery writer.
Love nature?
Mabel and Stanley love hiking on Mount Rainier. Wherever you live, you can visit its website at https://www.nps.gov/mora/index.htm, or find out more about America's best idea at https://www.nps.gov/index.htm, the National Park Service website.