I actually think I was thirteen going on fourteen when I first saw THE THIRD MAN, as part of Halifax CJCH-TV's nightly series of movies in the early evening.
I had read plenty of media account of the horrors of the Holocaust by then but hadn't really see anything cinematic about it, nothing to hit me really hard emotionally.
But THE THIRD MAN, centred on the morality of mis-used penicillin, did indeed hit me really hard.
No wonder, for it was a film that remains (65 years later) on many critics' lists of the top ten movies of all time.