Heving been brought up on the King James Authorised Version of the Bible, then I understood the meaning of "Adam knew Eve" at an early age. Indeed, I vaguely remember my elder brother and his pals sniggering occasionally at the double entendre - this also had to do with the fact that our surname is 'Adams'.

However, according to an article I read somewhere not so long ago, English-speaking Christians today are less drawn to the KJAV or other older translations, and prefer more modern ones, where it's a sure bet that the verb is not 'knew'. Presumably the knowledge of "Adam knew Eve" will fade away as KJAV readers do.