Abracadabra

Take a scary movie that occurs when one character is left in an empty house. The movie finishes, and suddenly there is no more sound. You've just been primed for fear by the movie, and your emotions are running high. A shadow moves outside, and you freeze for a moment, imagining the face of the axe murderer/psychotic prisoner/whatever right outside your window. You hear a noise, and your mind compiles all of the horrible and painful ways that you could be about to die. It happens. And then, the next time you're in a similar situation, you might start feeling the same way all over again. This is one way that you cannot trust your mind. The key to getting rid of this is to think, "Why am I scared?" And then, if you trace the fear back to a movie you saw, you ask yourself "Is it reasonable for me to be scared of a fictional creation?" This is a way that you can begin to trust your mind.

Alternatively, if you've lost a loved one, you might hear them, see them or feel them in particular contexts that evoke strong emotions in you. This is something that may never go away, but instead lessens over time.