Finally got round to reading Niven's biog this year (The Moon's a balloon), if you're an old fecker who's watched a lot of old movies, it's a great read.
Very clever that it never quite makes it clear whether it's real or all in his head. That bit of music that plays when he's about to have an episode is haunting too.
I thought the book ending up in his jacket and the last two lines make it clear it's real.
I have loved this film (and David Niven) since I was a kid. Glad others recognise its utter beauty and genius. Inspired decision on the colour pallette