Have you ever had the persistent feeling that you were out of place, or felt a sense of sadness that you will never know what will happen to your great-great-grandchildren? Some of these strange feelings have names. See how many you have experienced:

1. Opia.

This is the name given to the intense feeling of invasive arousal that one feels when engaging in mutual gaze-making direct eye contact with someone else. A great deal of research has been done on eye contact (see here), and it is well established that eye contact can be arousing. The arousal is often interpreted based on the circumstances. If the person is perceived as a threat, it is unpleasant. If two people are attracted to each other, it is pleasant and titillating.

2. Déjà vu.

Most everyone knows this one: It is the feeling that you've been someplace before or that you are repeating an event. Memory psychologists believe that this is caused by features from a past experience that are triggered by features of the new experience, which are similar in some way. Approximately 75% of people report experiencing déjà vu. ...[Continue reading on Psychology Today]