"to rack your brain(s)"
to think very hard, usually in order to remember something or to find a solution to a problem
Related words and phrases:
Two colleagues are talking ...
Colleague 1: I heard our biggest supplier went out of business last week.
Colleague 2: Yes. I have been racking my brain trying to think of how we can possibly find a replacement supplier.
Colleague 1: Have you come up with anything?
Colleague 2: Not yet. Our supplier was the only one on the entire west coast.
Colleague 1: Then I guess you had better think harder because if you don't find a replacement soon, it will be a disaster for us.
Two friends are talking ...
Friend 1: Are you ready for our big road trip south of the border this weekend?
Friend 2: I can't seem to find my passport.
Friend 1: Where did you put it?
Friend 2: I have been racking my brains for days. I remember coming home from our last trip and unpacking but no matter how hard I think, I just can't seem to remember putting my passport away. I must have had it with me or I couldn't have crossed the border to get back home.
Friend 1: Maybe you didn't put it away and it is still in the pocket of your suitcase?
Racking his brain for over an hour, he simply could not remember the address.
1) Was I insane? How did we stand each other? I rack my brain for instances of seeds of resentment planted during that first year.
2) ... healthy patient looking to stay healthy, this patient was a goad for me to rack my brain, and re-scour the relevant literature.
3) In an ideal world, I wouldn't have to rack my brain trying to pick just one natural gas company; ...
4) He spent the first three hours racking his brain before he remembered ...
5) ... thought back to his childhood, racking his brain to figure out where the Soviets might have laid their cables.
6) Generally, Vonnegut didn't seem to believe in racking his brain to come up with the exactly appropriate metaphor or description.
7) Instead, you're forced to remember exact directions or rack your brain to remember the route.
8) Briefly, you dismiss him and begin racking your brain for other strong contacts. There's the supervisor three jobs ago ...
9) ... new and innovative ways of growing your business, or managing your function? Futilely racking your brain for that creative spark or that one great idea ...
10) Instead of finding a place to go and then racking your brain to find a decent price, why not find the cheapest price first?
11) ... acquaintance at a party and attempt to gauge whether or not they remember you while racking your brain to recall their first name.
12) Sitting calmly and supportively when someone is upset seems like it would be easier than racking your brain for a solution, but I don't think that's the case ...
13) She says that through the summer of 2016, she racked her brain for new ideas about how activists could help, ...
14) For more than a month, Torjman racked her brain. Caledon's traditional donors were doing as much as they could.
15) Marilyn said she had been racking her brain for weeks, trying to figure out something special to give Randy for ...
16) She had spent weeks racking her brain over what to buy him.
17) There is much insecurity that people have, therefore they will be racking their brain unnecessarily.
18) He racks his brain for every instance of where the two of you could have possibly met.
19) Then, studying a jumble of photos of a factory in his textbook, he racks his brain over how to describe the production best.
20) He endlessly racks his brain to try and understand how that could be.