be beyond (one's) ken

To be 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.

Common Names:

Name	Pronounced	Usage
Andra	AN-drə (English)	Romanian, English
Kata	KAH-tah (Finnish)	Hungarian, Finnish, Croatian
Ngaio	-	Maori
Sarpedon	-	Greek Mythology
Christiana	kris-tee-AN-ə (English)	English, Late Roman
Jockie	-	Scottish