Did 'Twice Blessed' inspire Erich Kaestner?
Check out "Twice blessed" which already has been filmed in 1945
http://www.imdb.com/title/tt0038197/
and has the exact same story as Erich Kaestner's "Das doppelte Lottchen" which according to Wikipedia was not published before 1949:
http://en.wikipedia.org/wiki/Erich_K%C3%A4stner
The question is: did Kaestner watch "Twice Blessed" before 1949 at a German movie theater and then wrote the book inspired by the movie?
Or is it just co-incidence?