Lost -- Desmond's little ditty explained - VIDEO
The key to the song lies in Desmond's nationality. In case you hadn't noticed, he's Scottish (by the sounds of his accent, probably from Glasgow, possibly Paisley).
Henry Ian Cusick, the actor who portrays Desmond, isn't actually Scottish himself -- he was born in Trujillo, Peru. His father is Scottish, but he spent most of his early life in Trinidad and Tobago and moved to Scotland when he was 15.
Presumably, Scotland is where Ian (or perhaps his character, Desmond) developed an affection for the Glasgow-based football (soccer) team Celtic FC (pronounced sel-tik).
Celtic are one half of of two dominant Scottish football teams (both based in Glasgow), known as the Old Firm -- the other club being Rangers FC. Both clubs play in the Scottish Premier League, but also take part in European competitions.
Celtic play their home matches at Celtic Park, a 60,832 capacity all-seated stadium in the east end of Glasgow (it's usually packed full most weeks), which is nicknamed 'Paradise' by the fans.
The club anthem is known as 'The Celtic Song', written by Glen Daly -- which was the song Desmond was singing in the flashback. It's the club anthem, and airs over the stadium PA as the team emerges out on to the pitch before a match commences.
It seems unlikely that the creators of Lost would have inserted such a reference of their own accord, so it's fair to assume Cusick offered it as an ad-lib, perhaps to expand his character's back-story.
It's not that the song (or the reference) is obscure, but I just can't imagine that J. J. Abrams or Damon Lindelof would be too aware of Glasgow Celtic FC (unless they're members of the Los Angeles Celtic Supporter's Club, which I'm reliably told has a fairly big contingent).
However -- and this is where it starts getting interesting -- the episode writers were Brian K. Vaughan and Jeff Pinkner, and I know for a fact that Mr Vaughan is good friends with comic-book writer Mark Millar, who just so happens to be a Celtic fan...
It's entirely possible that Millar fed the line to Vaughan.
So, it starts to become easy enough to speculate on the connection between Desmond, Celtic FC and 'The Celtic Song' (I'm a football journalist based in Scotland myself, so I jumped to a conclusion almost instantly).
You're probably now asking yourself what I'm driving at.
Well, here it is: could it be that Desmond was making a subtle hint at the wider theme of Lost with the subtle connection to Celtic Park being nicknamed 'Paradise'?
Were the writers trying to tell us something about the Island via this little ditty?
Watch the clip again below from YouTube and judge for yourself...