beyond/outside your ken

outside (one's) ken

Advanced beyond one's ability to understand or make sense of the subject matter or task at hand. The stuff they're teaching in this advanced math class is outside my ken.
See also: ken, outside
Farlex Dictionary of Idioms.

beyond your ken

If something is beyond your ken, you do not know about it or understand it. The quirks of the antiques business were beyond his ken. The scientific subject matter is beyond the ken of the average person. Note: `Ken' here means the full range of someone's knowledge or understanding. The Scottish verb `ken' means `know'.
See also: beyond, ken
Collins COBUILD Idioms Dictionary, 3rd ed.

beyond your ken

outside your range of knowledge or understanding.
See also: beyond, ken
Farlex Partner Idioms Dictionary

beyond/outside your ˈken

(old-fashioned) not within your knowledge or understanding: Such things are beyond my ken.
Ken is an old word for ‘knowledge’.
See also: beyond, ken, outside
Farlex Partner Idioms Dictionary
See also:
  • beyond (one's) ken
  • beyond ken
  • beyond your ken
  • a bit beyond (one's) ken
  • ken
  • outside (one's) ken
  • be beyond (one's) ken
  • it's beyond me
  • above (one's) head
  • above your head