The book that has been torn apart by Scotty the dog, is a copy of the novel 'The Catcher in the Rye' by J.D. Salinger. Both the writer and the novel are referenced several times in the movie.
Zoe Kazan, who plays Ruby, also wrote the screenplay for "Ruby Sparks". Zoe's grandfather is Elia Kazan, who directed "On the Waterfront (1954)". Her mother, Robin Swicord, wrote the screenplay for "The Curious Case of Benjamin Button (2008)". Her father, Nicholas Kazan wrote the screenplay for "Reversal of Fortune (1990)".
In their way to Big Sur, when they stop a while near the sea and leave the car, Ruby is carrying a purse. Immediately later, when they are playing "who kills the other first" you can see no purse at all.
When Calvin is talking to his brother, there are two other people at the right side training on the stepper. After the camera swaps, the two people from the stepper are now at the treadmill.
"Ready" by Kovas. The complete list of songs can be found here with their corresponding scene descriptions.
Q
At the end what did Ruby actually mean by asking Calvin to "Start Over"??
A
Ruby in the literal sense meant that she thought she made a bad "first impression" on Calvin, so she asked if they could start over so she could make a better impression.In the more symbolic sense Ruby asked to start over because she had no recollection of Calvin, and they actually had the chance to start their relationship over.