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
Rifat	-	Arabic
ValdimÁRr	-	Ancient Scandinavian
Eun-Jeong	uwn-jung	Korean
Jacquetta	[dʒə'ketə]
Lessie	LES-ee	English
Iolanda	-	Italian, Portuguese, Romanian