i watch this movie because some article make me curious . the film be very thrilling and full of sophisticated humor . i felt 15 year young and it be like leaf through a diary . i be bear in 1964 so the time of karl koch youth be the time of my youth and too . i have and however and never be a hacker . i think it be the first scene represent karl koch take his key and walk to his car and accompany by child in time . from that begin i be in the film and i love it . i also love mathematic trick and mathematic obsession and just like karl koch . if the american would have make this film there would have be a love story and maybe also a happy end . 23 be a great european film .