Liz Evans, on whom the film's protagonist is based, is the mother of Wynne Evans, famous for his 'Gio Compario' character on the Go Compare adverts.
A lot of the action takes place on the stage of the actual Lyric Theatre, even down to the alley behind the theatre where the lorry is, stage door and foyer.
The Lyric Cinema, Carmarthen, actually screened a revival of "How Green Was My Valley" in 1967, some 26 years after it was made. Audiences tended to be vocally derisive, as Welsh audiences tend to be when confronted with the absurd inaccuracies of this famous film.
Liz Evans' original hair salon was on Lammas Street and not opposite the Lyric on King Street as depicted in the film.
Two members of the cast have been directed by Steven Spielberg: Samantha Morton (Liz Evans) in Minority Report (2002) and Joe Hurst (Huw Evans) in Ready Player One (2018).