The article text provided contains only website navigation elements (menu items such as "Music," "Film," "Travel," "Art," "News," "Shop," "Mailing List") repeated twice, with no actual article content about Keith Richards or his stated secret to longevity in rock music. As a result, there is no substantive text available to summarise accurately.

To provide a proper summary, the full article body would need to be supplied, as the current content does not include any quotes, details, or context about what Richards actually said.