Cycle mirrors and folding bicycles

We cycled down the Leine Valley in Germany last week. It rises or a least starts in Leinefelden in western Thuringia and flows into the Aller a tributary of the Weser 300 km farther on. It is a good run with the chance of visiting Göttingen and Hannover underway. The thing that amazed me was that we were both cycling on Bromptons. Normally we find that we have to answer numerous questions about the little treasures, but no I was asked several times a day about a mini clip-on cycling mirror on my glasses that I wear when touring. To the best of my knowledge they have been available in Germany for at least 20 years.