: The story is based on the watercolor-illustrated books by Belgian artist Gabrielle Vincent. Pennac, who was a pen-pal and admirer of Vincent, was invited to write the screenplay for the 2012 film adaptation.
: Both characters are misfits—Ernest is a musician who won't be a judge, and Celestine is a painter who won't be a dentist—representing the struggle to choose one's own path.
: Following the film's success, Pennac published "Le roman d'Ernest et Célestine" (released in Italy as Ernest e Celestine in 2013), which expanded on the movie's narrative.