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.