I'm always coming across similar things, Bert.
In today's Father Brown, the 'secret' brother with mental health issues who had been kept hidden in the attic had a strong reaction to his brother's fiancée when she sat down beside him, and the brother said "it's because he's never seen glasses before". But in the previous scene, said brother was sitting next to, and chatting amiably with, Father Brown - who wears glasses!