If our thinking was legitimate then the world would be a very unstable place due to the fact that we have so many mental judgments on our surroundings and the people that we interact with. Isn't it fortunate that some of us can actually realise that what we are often thinking is insane compared to the reality outside of our heads. When we entertain negative thinking and project our own mental illness onto others, or more to the point, when we are doing other peoples' thinking for them we are allowing them to rent our mental head space for free. Most people are too wrapped up in their own lives to even care or consider the insanity of what we are thinking about our surrounding environment and therefore it can be clearly seen that our negative thinking and projections are a complete waste of time and energy. It is this energy that we need to focus on what is in front of us though we have usually given our power away to mental projections that don't even exist outside of our head and they all stem from one thing which is fear. Fear of the past repeating itself or fear through anticipation of what will happen in the future or the next moment.
Keep your mind in check with your behind and that is now, right here in this moment - there is no other reality!