* AndYouThoughtItWouldFail: Before its release, there'd already been three OvernightAgeUp comedies [[FollowTheLeader made between 1987 and 1988]]: ''Like Father, Like Son'', ''18 Again!'' and ''Vice Versa'' (not to mention the Italian film ''Da grande'', which was this film's direct inspiration), so many expected this film to tank and be forgotten. Instead, ''Big'' became the highest-grossing and most highly-praised film of the bunch.
* BetterOnDVD: The extended cut elaborates further regarding Josh's wish to be big.
* EsotericHappyEnding: {{Website/Cracked}} has a particularly disturbing interpretation regarding [[http://www.cracked.com/article_18793_5-reasons-big-had-most-depressing-happy-ending-ever.html the movie's ending]].
* HilariousInHindsight:
** Tom Hanks's character works at a toy company. Years later, Hanks would star in [[WesternAnimation/ToyStory another movie involving toys]].
** The film features ProductPlacement for Pepsi. [[http://io9.com/5722906/the-real+life-location-of-the-zoltar-machine-from-big-is-now-occupied-by-a-pepsi-machine The location where the Zoltar was at the end of the film is now occupied by a Pepsi machine.]]
** At a board meeting, Josh is unimpressed by a Franchise/{{Transformers}} style toy that turns into a building, asking "[[WesternAnimation/BeastWars Couldn't it turn into a bug? Like a prehistoric bug?]]".
** At Josh's apartment, he has a model of a Saturn V rocket from the Apollo space program. Several years later, Tom Hanks would star in ''Film/{{Apollo 13}}''.
** Overlapping with TechnologyMarchesOn, Billy scoffing at Josh's interest in computer work is pretty funny now that computer skills are a very helpful thing to have.
*** The movie actually seems to have been aware of this, as it's his computer skills that get Josh a job.
*** Josh's idea for an electronic comic may also count as Defictionalization or LifeImitatesArt. While electronic texts existed in the late 1980s, e-books didn't start out-selling print books until [[TheNewTens the 2010s]].
* NightmareFuel: The Zoltar machine. Its overall appearance is bad enough (especially the glowing eyes when it's "working"), but the breathing sound it makes and the way the mouth opens and closes hugely is extremely disturbing. The scene when Josh discovers it's not plugged in thus manages to actually be chilling.
* SignatureScene: Josh and Mr. [=MacMillan=] playing the floor keyboard at FAO Schwartz.
* UnfortunateImplications: Not only does Susan fall for Josh, a 13-year old in an adult body; the reason she does in the first place is because of his childlike nature. ''Website/{{Cracked}}'' has pointed out these creepy pedophilic undertones in the movie several times.