It is universally accepted that the expression means that someone is blissfully happy, but there are debates about the origin. Askville writes that it was popularized by the Johnny Dollar radio show in the 1950s when the “…hero was knocked unconscious and transported to Cloud Nine.” Many think, or have thought, that the origin was the U.S. Weather Bureau which rates Level Nine as the very highest cumulonimbus clouds. Another theory is that it is derived from Buddhism in which “In the ninth stage the seeker reaches when all his acts are unselfish…” Then there is Dante’s Paradise in which the ninth level of heaven is the closest to the Divine Presence. If that doesn’t confuse you sufficiently, contemplate that the number nine turns up in other expressions with disputed origins such as “dressed to the nines” and “the whole nine yards.” Is searching for origins fun, frustrating, or interesting?