We all know what it’s like to wake up from a frightening dream and think, “Wait a minute! Was that real?” And once we get a little more alert, we realize that it was just a dream, and we hopefully fall back to sleep.

Psychologists say there is one type of dream that is nearly universal. Can you guess what it is? It’s the dream of being unprepared for an exam. It’s awful, isn’t it? School children all over the world report having this dream, or I should say, this nightmare, for that is what it truly is. In this dream, you realize on the day of the exam that you never showed up for class—you missed the entire semester. Or the exam questions are written in a foreign language you don’t recognize, or you completely forgot to study the night before.

Dr. Sigmund Freud, the founder of psychoanal…