Don't believe everything you think, and definitely don't believe everything everyone else thinks. Notice it. Question it. Pay attention, and then see how it correlates with reality. Do some research. If there is a discrepancy, reality wins. That doesn't mean you can't imagine something different or better for yourself, and work towards it. But, it does mean that you've got to notice, accept and deal with what's currently true. Acknowledge that what you think is so isn't always the case. Certainty doesn't equal fact. There is a subtle (or not so subtle) distinction here. Conscious, visceral pretending is powerful in the field of metaphysics; head-in-the-sand lying to your self is delusion. Thinking it's so may make it so in the future, but it doesn't make it so now. So...start to introduce a little "hmmmmm, maybe" into your thought patterns, especially when it comes to your assessment of other people's motives and behavior.