get your brain into gear
get (one's) brain in gear
To start thinking clearly and productively. Well, get your brain in gear because we need to solve this problem, and I don't want to be here all night!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
get your brain into gearor
get your brain in gearINFORMAL
If you get your brain into gear or get your brain in gear, you make yourself start to think clearly so that you can deal with something. Note: The image in the following idioms is of driving a car. All I want is to get my brain in gear and get back to the top. A long pause followed while he tried to get his brain into gear. Note: If you have your brain in gear, you are already thinking clearly and are ready to deal with something. It was too early in the morning — I didn't have my brain in gear. Note: Other nouns such as mind and head can be used instead of brain. It gives you a chance to think, plan and generally get your mind into gear.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012