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
Lazzaro	LAHD-dzah-ro	Italian
Archy	['a:tʃi]
Ferne	FURN	English
Dalia (2)	-	Lithuanian, Baltic Mythology
Nate	NAYT	English
Neta	-	Hebrew