PS I started driving (even before 16, with supervision) before electronic turn signals were ubiquitous. It was not pleasant having to roll down the window and stick your arm out when it was zero outside. But one did it, because, as you say, it communicated my intentions to other drivers. Driving is easier and safer for everyone when everyone knows what everyone else is planning to do. I signal all my turns, at an appropriate distance. It’s a reflex. Is that robotic? Probably. Much of what we do, even in complex tasks, is muscle memory rather than conscious decision-making. I don’t want to have to cogitate about whether to signal or not, every time I make a turn. I just do it. A bonus is that no one has to say about me, “Nice signal, A-hole*”, as I have to say so often about others.

In his book on emotions, Jack Katz says that “A-hole” is the most common term of endearment that drivers use for other drivers.

PS: No, that's not my style, Alarmist. Even in the daytime, but obviously at night, I assume that drivers can't see me, until I can actually see their eyes. You're putting on the signal was more than enough effort to get along with the guy.

It's gotten more dangerous to ride since the smart phones have come out.

PS

I had a bicyclist try to pass me on the right as I was signalling and pulling in to the right to park. He was nowhere near me when I signalled and pulled in. He then comes around to shout at me before riding off into the night dressed in black with no tail light.