See, some of these don't strike me as that silly.
Personally, I don't like animals, so I never try to feed/pet the squirrels that run all over campus, but lots of other people do. It's kind of a student tradition here, and I've never seen any emails or warnings about them. So someone coming from a situation like that, might very well appreciate knowing that the practice is not encouraged in their new location.
And, as a biologist, I know a fair amount about invasive species and how they get into the environment; but I'm not sure I'd expect the general public to be aware of this. I doubt they even realize their aquarium pets are going to survive being dumped into the local river--I figured most adults told their children this as a pleasant fiction. "We're setting Fishy free in the river!" while thinking Fishy will be toast in about ten minutes.
Though, I do think that if you actually move to an area to live, you should acquaint yourself with "natural hazards" like wildlife that gets into garbage or could eat your pets, and should not be taken by surprise by that.
My own contribution: I supervise undergrad students who work part-time in our office. Over the years I've had to explain to more than one that there are four
sets of numbers on a credit card, which they have to type into a website to order supplies for us. Not just three. Granted, the fourth set doesn't seem to have good contrast with the background of our office credit card, but I'm always boggled that they didn't even know it was there
. I guess they don't have credit cards, or if they have them, they've never really looked at them and have never bought anything online.