Shane's clarification isn't enough?
"It's just about a guy getting pissed at a bar round here," says Shane nonchalantly. "He's getting pissed because he's broken up with this bird and... you know how it is when you just go into a pub on your own to drink and it's really quiet and you get this old nutter who comes over and starts rambling on you. So this old guy starts on about how he came back from the war, the First World War. Or the Second. One of them anyway. And he tells him about the ship he had out there and how he got out and came back and this girl had fucked off with someone else, a girl with a pair of brown eyes. Which is the same situation as the young guy sitting there listening to all this rubbish and the juke box playing Johnny Cash and Ray Lyman and Philomena Begley, classic London juke box tracks. And in the end he gets to the stage where he says fuck it, and he goes stumbling out of the pub and he walks along the canal and starts feeling really bad, on the verge of tears, and he starts realising that the old guy has had a whole fucking lifetime of that feeling, going through the war and everything, but his original reaction is to hate him and despise him. I'm not saying he goes back and starts talking to him but you know... "
(from an interview with Shane, Pogueology, Folk Roots, August 1987, published at Poguetry.com website)
Eagles may soar, but weasels don't get sucked into jet engines.