bang (one's) head against a 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 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 wall trying to convince everyone.

Common Names:

Name	Pronounced	Usage
Ansteys	['ænstiz]
CianÁN	-	Irish
Rowley	-	English
Sigalit	-	Hebrew
Anapa	-	Egyptian Mythology
Brittny	BRIT-nee	English (Modern)