go off (one's) rocker

To become crazy or mentally unsound; to become extremely foolish or foolhardy. I'm going to go off my rocker if I have to hear that blasted song once more! I think Jane's grandmother has gone off her rocker lately. You must have gone off your rocker if you think that's a good idea!

Common Names:

Name	Pronounced	Usage
Terzo	TER-tso	Italian
Roselyn	ROZ-ə-lin	English
Henriette	awn-ree-ET (French), hen-ree-E-tə (German), hen-ree-ED-de (Danish), hen-ree-ET-te (Norwegian)	French, German, Dutch, Danish, Norwegian
Annas	AN-əs (English)	Biblical, Biblical Latin
Marvin	MAHR-vin (English), MAHR-veen (German)	English, German
Verochka	-	Russian