before one knows it

== English == === Phrase === before one knows it rapidly (and sometimes unexpectedly) ==== See also ==== before you can say knife === Further reading === “before you know it” in Longman Dictionary of Contemporary English, Longman. “before you know it”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present. “before one knows it”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.