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
Avril	av-REEL (French), AV-ril (English)	French (Rare), English (Rare)
İBrahİM	eeb-rah-HEEM	Turkish
Zikmund	-	Czech
Laarni	-	Filipino
Fen (1)	-	Chinese
Babur	['ba:bʊə]