Our own feeling about thirteen, especially when joined with Friday, has added another to the long list of phobias; treiskaidekaphobia, or "fear of the number thirteen" (some of the other phobias are the well-known claustro-, acro-, and agora-, fear of being closed in, of heights, of open spaces, respectively; less known are ailurophobia, "fear of cats," iatrophobia, "fear of doctors," nucleomitotophobia, "fear of atomic bombs," mageiricophobia, "fear of having to cook," and, recalling FDR, phobophobia, "fear of fear itself.")