People experience deja vu differently. Some are terrified of the experience while others feel a mild euphoria. Since it only occurs for about 30 seconds, it doesn’t really have a tremendous effect on anyone’s consciousness. Unless if it cause anxiety.
Some people associate the phenomenon with clairvoyance or a premonition. This often cause problems, because they will tend to use the phenomenon as a factor in their decision making. However, there has been no proof whatsoever that deja vu is a precursor of things to come. It really does depend on how you interpret the experience.
Many Eastern religions believe that deja vu is simply a case of memories of your past lives that surface.