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
Baltassar	-	Biblical Latin
Nanna (1)	NAN-nah (Danish), NAHN-nah (Swedish, Norwegian, Icelandic)	Danish, Swedish, Norwegian, Icelandic, Norse Mythology
Monty	MAHN-tee	English
Savva	-	Russian
Zeynab	-	Azerbaijani, Persian
Walter	['wɔ:ltə]