We limit our ability to perceive reality by becoming satisfied with things as they are or seem to be. A chair will always be a chair, and should remain placed just so on the floor. However, the Creator is infinite in All ways, including possibilities. Perhaps a person from another dimension but invisible to our eyes might be sitting in it. It is our limitation in thinking that limits our ability to perceive reality.
Mysticism is the science of removing mental limitations.
A mystic is one who learns through practice to be able to look behind the veil of limitations and sees more clearly with more senses awakened. We're talking here about the ability to hear what others think, or seeing and hearing other beings, or passing back and forth through time. However, without a ground of tradition, a guide, or a map, these abilities can become dangerous to the individual and others. They can become unsettling and even lead to psychosis. Within mystical traditions such as Sufism, these abilities are expected to arise, and are markers along the path.