To Antony, who was older and who realized into what deep waters they were getting, it did not seem fun. But it was amazingly interesting. He saw so much, and yet somehow it was all out of focus. It was like looking at an opal, and discovering with every movement of it some new colour, some new gleam of light reflected, and yet never really seeing the opal as a whole. He was too near it, or too far away; he strained his eyes and he relaxed his eyes; it was no good. His brain could not get hold of it. But there were moments when he almost had it ... and then turned away from it. (Vintage Books 2008, p. 121)