Angle Shades - Phlogophora meticulosa (Phlogophora meticulosa)

Perhaps not immediately apparent from my photograph but I had stood in front of this plant for some time before I suddenly noticed this moth whose camouflage technique looked much like the dying leaf it was clinging to.
Although I expect science and books would provide the answer I am still fascinated at how these and other insects seem to know which dead leaf , plant , tree or wall are best suited to their shape , colour or wing pattern to hide on. Some do it so well they virtually disappear completely.
Probably fanciful thinking on my part but this moth seems to have matched the lines of part of its wing pattern to the contour of the crinkled leaf.