Shaun,
I saw just a bit of a gripping film one Saturday afternoon when I was fourteen, but at school on the Monday I couldn't find anyone who'd watched it; I was dying to know the dénouement!
Channel-hopping late one night - seventeen years later - I tuned into something that all of a sudden seemed familiar.
It turned out to be
that film, which was
Beyond a Reasonable Doubt (from 1956 and starring Dana Andrews) and the twist at the end was worth waiting for (maybe not for all that time though).
So I can relate to a nigh-on twenty-year itch as well!
Jayne