cudgel one's brains

There is no need to cudgel one's brains much in this game," said Don Luis to the count; "I think I understand it already.

Nor was this a question of trifles: one may cudgel one's brains endlessly in advance, but some new requirement will constantly be cropping up -- until one puts a full stop to it by casting off and sailing.

Nor was this a question of trifles: one may cudgel one's brains endlessly in advance, but some new requirement will constantly be cropping up — until one puts a full stop to it by casting off and sailing.