Just because a thought or message comes from our mind, does not necessarily make it true. We tend to take any messages our mind tells us as fact and never second-guess them. This can include that mind chatter that we suffer from that can limit us from our greatest potential. Most people assume that everything our brain tells us is true. It is not.
Our thoughts are made up, as is everything else including language. They are snippets of impressions from the world around us. Greatly influenced by our environment, information we receive and people we spend time with.