Not understanding a EULA is not "not understanding the law". A EULA isn't a law. If we assume that the EULA is part of a contract, then you may not be understanding part of a contract, but that has nothing to do with not understanding the law.
If you are a consumer, there are plenty of laws in most countries that protect you from your own stupidity when entering a contract to some degree. So "punishing" you for doing something against the EULA will be difficult. It is a civil contract, things might go to a civil court. But terms that you cannot understand may very well be interpreted in your favour. If the court decides that someone created a 50 page EULA to trick you into violating it, there's a good chance it will be thrown out altogether.
If there are terms that only a lawyer can understand and not a normal consumer, they will likely be thrown out. If there are terms hidden in a 50 page EULA that nobody is every going to read, they will likely be thrown it. However, that's because you couldn't be expected to understand things. If the company in question explains relevant parts of the EULA to you, then after getting the explanation you'd be unlikely to be protected by your ignorance.
And as a last measure: For software the situation is usually that you are asked to accept a EULA in order to be allowed to install and use the software. You can always claim that you didn't accept the EULA (and nobody can prove otherwise) and be guilty of copyright infringement, so that is the absolutely worst that can happen to you.
If you are a company, things are different. There's no consumer protection in play.