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
Darby	DAHR-bee	English
Tenskwatawa	-	Native American, Shawnee
Cherokee	CHER-ə-kee	English (Rare)
Myrtle	MUR-təl	English
Lovett	['lʌvit]
Kotryna	-	Lithuanian