We sometimes accept a core believe as the truth without questioning it. As core beliefs accumulate over the years they eventually make up a system that functions in much the same way as a computer’s operating system. Running in the background at such a discreet level, we are usually not even aware it is there.
Our core belief has been developed since we were a child. This is due to the result of a great many factors, including but not limited to, the way we were influenced by our parents, siblings and other significant people in our lives. By the time we reach adulthood we have some pretty fixed opinions of ourselves and the world around us. And once installed, these beliefs are rarely updated unless the whole system crashes!