The ancients believed that the ‘I’ in the mind is a reflection of the body. Just as athletes and sports people develop muscle memory, the bodymind retains the imprints of experiences that shape your memories, emotions and desires, which in turn form the basis of your conscious and sub-conscious choices and actions. Who you are is a reality of your own making.
Aside from drugs, sleep deprivation, extreme physical experiences or direct physical interference, nothing or no one can reach into your head and make you do or believe something against your will – all your beliefs and actions are a result of choices you make, knowingly or unknowingly based on long held beliefs or reasoned, considered thought. The world is not simply and only something ‘out there’, you construct a view of and feelings about something ‘out there’ and make sure it suits the feeling you want or allow yourself to have about it at that moment and in that situation.
Neuroscience is a fast developing field that explores this aspect of who we are.
A very good guide is Neuroscience of Self and Self-Regulation by Todd F. Heatherton
As a social species, humans have a fundamental need to belong that encourages behaviors consistent with being a good group member. Being a good group member requires the capacity for self-regulation, which allows people to alter or inhibit behaviors that would place them at risk for group exclusion. Self-regulation requires four psychological components. First, people need to be aware of their behavior so as to gauge it against societal norms. Second, people need to understand how others are reacting to their behavior so as to predict how others will respond to them. This necessitates a third mechanism, which detects threat, especially in complex social situations. Finally, there needs to be a mechanism for resolving discrepancies between self-knowledge and social expectations or norms, thereby motivating behavior to resolve any conflict that exists. This article reviews recent social neuroscience research on the psychological components that support the human capacity for self-regulation.