[1] Juster enlisted in the Civil Engineer Corps of the United States Navy in 1954, and rose to the rank of lieutenant junior grade.

During one tour, to combat boredom, he began to write and illustrate a story for children, but the commanding officer later reprimanded him for it.

[3]: xvii  Still, Juster also finished an unpublished satirical fairy tale called "The Passing of Irving".

[3]: xviii  Later posted in the Brooklyn Navy Yard, again to combat boredom, he made up a non-existent military publication called the Naval News Service as a scheme to request interviews with attractive women.

[3]: xviii Approximately six months after meeting Feiffer, Juster received his discharge from the Navy, and worked for a Manhattan architectural firm.

[2] Juster went on to author Alberic the Wise and Other Journeys (1965), Stark Naked: A Paranomastic Odyssey (1969), Otter Nonsense (1982), and As Silly as Knees, as Busy as Bees (1998), among other works.

[1] He also published A Woman's Place: Yesterday's Women in Rural America in 1996 for an adult audience, based on his personal experience of residing on a farm in Massachusetts.

[7] He also co-founded a small architectural firm, Juster Pope Associates, in Shelburne Falls, Massachusetts,[8] in 1970.