Similar tale, although not cycling. I used to own a Honda CRX - loved that car - and I was also a moderator and founder member of the UK owners‘ club, hence I got to see a lot of them in various guises.
One peculiarity of Hondas of that era (and many Japanese cars actually, as well as older British cars) is that the indicator stalk is on the right of the steering column. Perfectly sensible for a RHD car if you ask me but overtaken by mass manufactured European and America designs with LHD steering columns transplanted to the RHS. I digress.
One day I got to have a drive of a heavily modified CRX, fitted with a turbocharger. That was a well-done project - idled as smooth as anything, but pulled like a train in any gear. Anyhoo, as I approached a junction I went to indicate and flipped the wipers on. Despite this being a CRX with the same setup as mine, because I wasn’t in my car I automatically flipped to “every other car” mode, since every other car I drove had the indicators on the left.