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
Yngvarr	-	Ancient Scandinavian
Wojciech	VOI-chekh	Polish
Kara (2)	-	Turkish
Florent	-	French
Reynard	RAY-nahrd, REN-ərd	English (Rare)
Muscowequan	-	Native American, Cree