Off the top of my head, there are a couple of examples that might change your mind. Freeway road signs. They need to communicate what lane to be in to a broad range of drivers, in stressful situations, very quickly. You should never notice a good interchange sign. a quick glance is enough to know you need to be in the second or third lane. A bad sign leads to bad driving, or a missed exit, depending on the aggression of the driver.

Airport signage is another pretty good example. I always look for the little man/woman symbols with an arrow pointing to the restrooms. I've missed signs that actually say "Restrooms ->" because there's so much visual clutter in airports. And i'm usually tired and a bit stressed out about making my connection.

Perhaps it is pseudoscience. In this context, I'd be willing to agree it's all just learned conventions. I'd argue, studying those conventions, and exploiting them is more than nothing though.

You should never remember a good sign. it's noticed, used and forgotten. You will always remember a bad sign.