beyond (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 beyond my ken.
beyond one's ken
outside the extent of one's knowledge or understanding. Why she married that shiftless drunkard is beyond our ken. His mean attitude to others is quite beyond my ken.
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'.
beyond your ken
outside your range of knowledge or understanding.