Define I Get It, French Class Meaning

I Get It, French Class
Said to someone who's extremly slow at understanding something just as they get it. This mimics the end of 'Honey I shrunk the kids' where it takes one kid the entire film to get a joke.

Dave: a horse walks into a bar, the barman say's why the long face?
Sara: I don't get it...is the horse sad?....er....Oh cos Horses have got long heads.
Dave: Oh I get it, French Class!!
By Kalina