* {{Defictionalization}}: That computer game Josh plays? [[http://www.bomtoons.com/biggame.html Someone went ahead and made it for real]].
* HeyItsThatGuy: [[ThatSeventiesShow Kitty Forman]] is Miss Patterson, Josh's secretary.
** [[Film/IndependenceDay General Grey]], what are you doing running a toy company?!
** [[Series/{{Weeds}} Celia Hodes]] also hooks up with a man-child.
*** Mr. Walsh from Beverly Hills, 90201 gives Josh his first paycheck.
* TheOtherMarty: Invoked during filming. Reportedly, Penny Marshall had David Moscow perform scenes of the grown-up Josh to help Creator/TomHanks get a handle on a how a kid would behave in an adult setting.
* TheRedStapler: Since its first release, many people have stopped by the FAO Schwartz on Fifth Avenue to play the floor keyboard.
* ThrowItIn: The "Big rap" sung by Josh and Billy is one Creator/TomHanks' son had learned while at summer camp.
** The scene where Josh and Billy shoot Silly String at each other was derived from Hanks, Rushton and Moscow being left in a room filled with toys.
** At the fancy party with baby ears of corn, Josh' eating the tiny ear as one would a normal one was put in by Hanks.
* TomHanksSyndrome: This movie marks Tom Hanks' transition from a comedic actor to a dramatic actor, even though the movie was part comedy, part drama.
* WhatCouldHaveBeen: RobertDeNiro and Creator/HarrisonFord were considered to star as Josh when he becomes an adult. Creator/SeanPenn was also considered for the role. Also, Debra Winger was offered the role of Susan, but she turned it down because she was pregnant at the time. She even recommended Elizabeth Perkins for the part.
** Creator/StevenSpielberg considered directing the film (his sister co-wrote it, after all) but declined as his son had been born and felt he should be closer to him. Creator/RonHoward and Sidney Pollack also turned down the directorial job.
** [[spoiler:The film was originally supposed to end with Josh back in school and meeting a girl named Susan -- who turns out to be the same Susan Josh met in his time as an adult, and made a wish on the Zoltar machine to become a kid again. This was rejected by test audiences and replaced with the ending where Susan watches as Josh turns back into a kid and walks out of her life.]]