yes, shona, you're right, it is closer to translation or even a meme-- the idea that grain could be fermented and distilled and the liquid extracted was "the water of life".
as for the migrations, well, by the time roman culture was reaching ireland, it was falling apart in rome.. and the culture that did get saved and transmitted to ireland was changed by irish.. and as for the irish and the scandinavians-- well the norsemen didn't just visit england.. they were well known in ireland too.
a few years ago i saw a scandinavian film (originally produced for scandinavain TV) "Under the Glacier" one of the characters was married to a an irish woman who was a silky.
all the stateside reviews went to lengths to explain what was going on, but apparently it was clear enough to the original audience. They might not believe in silkies, but knew about them. Bel doesn't celebrate the 4th of july, but is likely to be familiar with the holiday. cultures cross bounderies.
