a bit 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 a bit 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.