Can anyone explain why the vampires in that stayed young for a long time and then, suddenly, aged very quickly? And why did it happen to David Bowie before Catherine Deneuve, even though she'd been a vampire for far longer?
In the book the film was based on, Catherine Deneuve's character was in fact a different species, and did not suddendly age very quickly, because they had not lived beyond their years. The human companions they chose could enjoy an extended life before their body gave up, leaving them unable to die, but in a decrepit state. The film uses a favorite cinematic effect and to my mind suffers for it.