A brain in a dream often symbolizes your wisdom, intellect, knowledge or that which is currently on your mind. For example, brain cancer means that you are allowing something to consume your thoughts and it is reaching an unhealthy level. Brain surgery can symbolize a need to improve your thought patterns, get a better mental attitude. An exposed brain can either mean it’s time to open your mind to new things or it can be connected to you feeling vulnerable after sharing what is on your mind.