Ignorance of the Law is No Excuse

I think we can all agree that if ignorance of the law was an excuse, we’d get a lot more people falsely claiming ignorance in order to shirk responsibility for their crimes.
However, such a policy also requires that people are, in fact, aware of the law in question.
Essentially everyone knows it’s illegal to exceed the marked speed limit on a street (though enforcement of such laws is often given a bit of wiggle room), it’s illegal to assault another, rob banks, or other such actions. Knowledge of such laws are common.
In many cases, however, people aren’t aware of specific laws — such a law may not be something that a reasonably person might expect to exist (as opposed to, for example, a law against robbing banks), or the law may have recently been changed.
For example, it’s my understanding that using lead shot while hunting waterfowl is illegal. While not exactly common knowledge outside of the waterfowling community, all the bird hunters I know are well aware of the prohibition. However, how many people are aware that the use of lead ammunition if illegal in wide swaths of California (evidently to protect condors from ingesting bullets and getting lead poisoning)? There’s a lot of people who have been shooting regular lead ammo in California for decades before the law changed — the passage of such a law is not exactly common knowledge (it wasn’t reported in the media), and many of these shooters don’t subscribe to any newsletters, blogs, publications, or other means of learning about such a law. Very few people wake up in the morning and think, “I wonder if shooting lead ammo is still legal. I should check.” Unknowningly, these people become criminals when they go out to the woods to shoot as they had for decades.
Same thing with so-called “assault weapons” in California — when the state changed the law to require registration (and eventual prohibition) of such guns, very few people complied. While I’m sure that a not-insignificant number of shooters said “Screw that.” and didn’t bother registering out of idealogical reasons, I’d imagine that most gun owners were simply unaware of the law and remain unaware to this day as nobody has made them aware of the law, and they wouldn’t ever think of checking as the concept of a ban based on cosmetic features is so non-common-sensical that the thought would simply never occur to them.
When the ATF has to split California’s gun laws into two parts because they’re so numerous, I think that exceeds some sort of threshold. The average person should not need to consult a lawyer to ensure that their everyday actions are not in violation of some law that they’ve never heard of.
While ignorance of the law isn’t an excuse, such a policy requires that the average person can reasonably be expected to know the law. With the huge amounts of laws covering the minutest aspects of one’s life, I don’t believe it’s reasonable that an average person be expected to know every single law.
What can be done? Repealing onerous, obscure, or obfuscated laws seems…unlikely. Sending citizens an annual list of laws that apply to them will simply waste money for printing and postage; even if someone did read all the laws in such a document, it’s unlikely that’d be able to read all of them before the next edition arrives. If they did manage to read them, it’s unlikely they’d understand them all or how they apply without consulting a lawyer. Any sort of simplified “Legal FAQ” is likely to leave out information that applies to some groups.
Honestly, I’m not sure how things can practically be made better without some fundamental change in the law (see the aforementioned repealing of various laws).