bang (one's) head against a brick wall

To attempt, continuously and fruitlessly, to accomplish some task or achieve some goal that is or seems ultimately hopeless. I feel like I've been banging my head against a brick wall trying to understand this math equation. Some people are never going to agree with you on this, so it's no use banging your head against a brick wall trying to convince everyone.

Common Names:

Name	Pronounced	Usage
Mitchell	MICH-əl	English
Bonita	[bə'ni:tə]
Yakira	-	Hebrew
Winfred	['winfrid]
Tryphaina	-	Biblical Greek, Ancient Greek
Genevieve	['dʒenəvi:v]