Don't forget too that in this version, when Oisin returns, he rides as a giant amongst the people, his fianna have passed away, so either Tir na nOg has enhanced his stature or men are now shorter and less strong than they used to be and thus less fairy-like than Oisin or the Fianna (a 'decline from a golden age' motif). But I guess Mr O'Kelly knew what he meant when he wrote it.

The medieval version has 140 verses, and include his adventures in Tir na nOg.

I've loved the Pat Kilbride version ever since I got hold of the vinyl 'Rock and Roses' in the eighties.