66-odd provinces of old Japan; (lit.) 60-odd states
Buddhist pilgrim (carrying 66 copies of the Lotus Sutra to be left at sites across Japan)
the 64 hexagrams (of the Book of Changes)
beginning to learn (something) when one is old; not being too old to learn
64th note; hemidemisemiquaver; semidemisemiquaver
an old man is twice a child