I was laying in bed in the Ashers garret,” Paul remembers in his “Many Years From Now” book, “and there’s a nice twilight zone just as you’re drifting into sleep and as you wake from it; I always find it quite a comfortable zone, you’re almost asleep, you’ve laid your burdens down for the day and there’s this little limbo-land just before you slip into sleep. I remember thinking that a children’s song would be quite a good idea and I thought of images, and the color yellow came to me, and a submarine came to me, and I thought, ‘Well, that’s kind of nice, like a toy, very childish yellow submarine