Jack grew up in Howick, Auckland. His mother was a radiographer; his father was a school teacher who had emigrated from Northern Ireland.[2] He has earned at least five degrees, including a PhD in law (supervised by Bill Hastings),[5] a master's degree in public policy, and degrees in ancient history and classical Greek.[2] He also holds qualifications in teaching English as a second language, quantity surveying, and diamond grading.[2]
His work during his time as chief censor included the Classification Office banning objectionable slogans and artwork on Wicked campervans. He said in an interview, "These are four-foot high mobile billboards advocating the consumption of illicit drugs using characters that are understood, attractive and recognised by children and that's just not OK."[2]
As of 2016, Jack lived in Vogeltown, Wellington with his wife Jan and their three dogs.[2]
