I don’t think your brain learned about one way streets and started fully trusting drivers to follow the law, certainly not the low-level parts that govern the “there’s something there you may need to pay attention to” mechanism.
I usually am aware that I'm in the middle of the street when I'm not supposed to be there (think when there's something blocking the sidewalk or similar). In this case, I'll absolutely pay a lot of attention to my surroundings. Hell, even when I cross the street at a green light, I'll look before I step off the sidewalk.
Because in my mental model of traffic, drivers are very likely to not follow the law.
I may very well be in the right and the guy running me over may very well be certain to get convicted, but what good does that do to me if my legs are broken or worse?
I think it's the same thing with the new electric cars, which have to make a noise because people can't hear them coming otherwise. This, to me, means that pedestrians are expected to pay at least some attention to their surroundings. Which, of course, doesn't mean you should run them over or otherwise put them at risk if they're careless.
But my overarching point is that enough people don't pay attention even when they are expected to, and no amount of noise is going to change that.
Behold, the dialectic of the material conception of the human mind. In my mind it bears an uncanny resemblance to the liquid humours posited by our forefathers, no?
I don’t think your brain learned about one way streets and started fully trusting drivers to follow the law, certainly not the low-level parts that govern the “there’s something there you may need to pay attention to” mechanism.