racked one's brain

Strained to remember

To rack one's brain is to strain mentally, searching hard for a memory, solution, or idea: I racked my brain trying to remember where I'd left my keys.

The image is of the medieval torture device that stretched victims—here applied to intense mental effort.

Sometimes spelled "wracked," though "racked" is standard.

Related

think hard · remember · think back · deliberate · reminisce · mull over · troubleshoot · scratch one's head · recollect · contemplate · lost in thought · scrutinize · chew over · puzzled · perplexed · stressed · overwhelmed · analyze

Opposites
cognitive effort

racked one's brainintuited

Perceived without conscious reasoning

no-brainer

mental engagement

racked one's braindrew a blank

Failed to remember

blanked out · zoned out · spaced out · let it go · daydreamed

Family

rack, racked, racking, racks, brain, brains, brained, braining, brainy

Familiarity
Top 100,000
Profile
Known to kids · Used worldwide · Timeless · Everyday, not technical · Rated G