beat (one's) head against a stone 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 beating my head against a stone wall trying to understand this math equation. Some people are never going to agree with you on this, so it's no use beating your head against a stone wall to try and convince everyone.

Common Names:

Name	Pronounced	Usage
Laurentina	-	Ancient Roman
Jos	YAWS	Dutch
Govannon	-	Welsh Mythology
Kavitha	-	Indian, Telugu, Tamil, Kannada
Alexandra	al-əg-ZAN-drə (English), ah-lek-SAHN-drah (German, Romanian, Spanish, Italian), ah-lək-SAHN-drah (Dutch), ə-lə-SHAN-drə (Portuguese), ə-lə-SHAN-drə (Brazilian Portuguese)	English, German, Dutch, French, Swedish, Norwegian, Danish, Icelandic, Greek, Portuguese, Romanian,
OldŘIch	-	Czech