Not all dreams fall into common categories, and even those that do often branch out in various directions. But there are some universal themes that people report time and time again.

Below is a list of 20 common themes, excerpted from dream expert Alan Siegel's Dream Wisdom: Uncovering Life's Answers in Your Dreams (Celestial Arts, 2003). Keep in mind, though, dreams that recur throughout your lifetime might have different meanings at different times, says Siegel.

Universal Themes: