I watched this movie because some articles made me curious ... the film is very thrilling and full of sophisticated humor. i felt 15 years younger, it was like leafing through a diary. I was born in 1964 so the time of Karl Koch's youth was the time of my youth, too. I have, however, never been a hacker. I think it was the first scene: Karl Koch takes his key and walks to his car, "accompanied" by "Child In Time". From that beginning I was in the film and I loved it. I also love "mathematic tricks" and "mathematic obsessions", just like Karl Koch. If the Americans would have made this film there would have been a love story and maybe also a happy-end. 23 is a great European film.