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
Selena	[si'linə]
Iphigenia	-	Greek Mythology (Latinized)
Vivi	-	Danish, Swedish, Norwegian
Vecheslav	-	Medieval Slavic
Baghdasar	-	Armenian (Rare)
Ryley	RIE-lee	English (Modern)