Marisa Tomei's character is revealed to be Robbie's English teacher when she first meets Cal at the bar, as she is wearing the same watch and bracelet seen when she writes on the blackboard earlier in the film.
The name plate on Emily Weaver's desk had a second line, "Associate to the Vice President," not "Associate Vice President." This is undoubtedly a reference to Steve Carell's TV series The Office (2005), in which there was a running gag about Dwight Shrute having the title "Assistant to the Regional Manager," not "Assistant Regional Manager."
The cocktail that Jacob drinks and makes throughout the movie is an "Old Fashioned," considered by some historians to be the first American cocktail. The recipe usually included sugar and bitters muddled together, club soda and ice, rye whisky, and a large slice of orange peel.
When Jonah Bobo's character, Robbie, is deleting Jessica's number from his cellphone, you can read that another contact in his phone is "Joey K." Joey King is the name of the actress playing Molly, his younger sister on screen.
When Ryan Gosling and Steve Carell discuss getting "Mr. Miyagi'd," Gosling grabs Carell's nose and squeezes playfully, saying, "Honk!" This is a reference to The Karate Kid Part II (1986) where Miyagi honked the nose of an opponent instead of striking him.
Emily Weaver tells Cal that she went to see the new Twilight movie and states that it was "so bad". Funnily enough, Julianne Moore and Twilight star Kristen Stewart went on to play mother-daughter in Still Alice (2014).
The trivia items below may give away important plot points.
In the film, Cal and Emily had Hannah when they were teenagers, but in real life, it is very realistic that Steve Carell and Julianne Moore could be Emma Stone's parents, since Carrell is 26 years older than Stone and Moore is almost 28 years older.