beyond one's ken:

 begin quote from: the kenning.

 beyond one's ken, "beyond the scope of one's knowledge" and in the phonologically altered forms uncanny, 'surreal, supernatural', and canny, 'shrewd, prudent'. Modern Scots retains (with slight differences between dialects) tae ken 'to know', kent 'knew' or 'known', Afrikaans ken 'be acquainted with' and 'to know' and kennis 'knowledge'. Old Norse kenna (Modern Icelandic kenna, Swedish känna, Danish kende, Norwegian kjenne or kjenna) is cognate with Old English cennan, Old Frisian kenna, kanna, Old Saxon (ant)kennian (Middle Dutch and Dutch kennen), Old High German (ir-, in-, pi-) chennan (Middle High German and German kennen), Gothic kannjan < Proto-Germanic *kannjanan, originally causative of *kunnanan 'to know (how to)', whence Modern English can 'to be able'. The word ultimately derives from *ǵneh₃, the same Proto-Indo-European root that yields Modern English know, Latin-derived terms such as cognition and ignorant, and Greek gnosis.^[1]