A fun/interesting/unfortunate/fortunate consequence of the mental world model of Inside Out (2015 Pixar film) (which is a great movie, and I’m saying this as a non-movie-type — I laughed, and I cried, and just omgwtfbbq Disney/Pixar) is that imaginary friends that are capable of autonomous flight are probably immune to being forgotten.
(Somebody told me to update…)