Nora,
I hadn't noticed that - but it prompts me to raise something which has been bugging me for some time. My father would call this a 'Library coincidence'. Another example would be learning a new word in the Listener then hearing somebody use it a few hours later. 'Library' presumably refers to the tendency for two books side by side in a library to be, mirabile dictu, about roughly the same subject. My family have been unable to find a source for the term Library Coincidence. Can anybody help? If Listener solvers are unable to help, I will be forced to conclude that the term was made up by my late father.