'Ditto'

When you hear the word 'Ditto' what do you think it means? The dictionary term for Ditto is: Used in accounts and lists to indicate that an item is repeated (often indicated by ditto marks under the word or figure to be repeated).
This is according to Dictionary.com . When I hear it, I remember the quote from the movie Ghost; 
Sam: I love you Molly. I always have. 
Molly: Ditto. 
In reference to the movie Ditto means "the same as stated above or before." In this case: "I love you too." It's kind of simular to "likewise"