In general, a defendant is not entitled to assert a mistake of law as a defense. (See 1 Witkin & Epstein, Cal. Criminal Law (3d ed. 2000) Defenses, 37, pp. 368-369.) " 'If the act itself is punishable when knowingly done, it is immaterial that the defendant thought it was lawful.' Criminal intent in a general intent crime 'is merely the intent to commit the prohibited act, not the intent to violate the law.' For example, in People v. Young (2001) 92 Cal.App.4th 229, 235, 237, the Court of Appeal held the defendant's belief that the marijuana he was carrying was medicine under the Compassionate Use Act of 1996 . . . and therefore he was acting legally was a mistake of law, which was not a defense to the general intent crime of transporting marijuana. ' " 'It is an emphatic postulate of both civil and penal law that ignorance of a law is no excuse for a violation thereof. Of course it is based on a fiction, because no man can know all the law, but it is a maxim which the law itself does not permit anyone to gainsay.' " ' " (People v. Cole (2007) 156 Cal.App.4th 452, 483.) On the other hand, "mistake of law can be a valid defense when the crime requires specific intent if the mistake of law negates the specific intent of the crime. But because section 25210 is a general intent crime--not a specific intent crime--mistake of law is not a defense to the crime." (Ibid.)