Finnegan's Wake

I've been thinking about it lately. The song, not the novel. The one about the Irish drunk who has too much of the "pure stuff" one morning, falls off his ladder and breaks his skull. Then, a fight breaks out at his wake, they spill whiskey on his corpse and he wakes up.

This is something I've always struggled with. The song hides a somewhat profound symbolism - whiskey means "water of life" - and in this case, it is both the cause of his death and his revival. What I am curious about, is whether this symbolism was intentional, added by the author, or whether it is something which was recognized later, by the eggheads doing analysis on James Joyce.

And if it was intended by the author, can we assume that some guy who came up with a street song in Dublin was clever enough to imbue it with such subtle symbolism?