But when you step into the street and see an oncoming bus, your body reacts immediately, almost as a reflex. Because the reaction requires immediacy, it must be involuntary. Logical, outer brain thinking is too slow to save you from the bus. You do not decide to feel a certain way when a bus is coming toward you. Instead, your body reacts. Your “reptilian” brain elicits a chain reaction, making you extremely uncomfortable. That prompts you to take immediate evasive action, a process over which you do not have conscious control.