If you can remember your dreams, chances are you're intrigued by them. Whether it's their utter mundaneness (your basic work dream) or their surrealism (your basic "eaten by a neon sea creature" dream), your dreams might be on your mind all day long.
If you have a hard time understanding your dreams, you're certainly not alone. We've been trying to pin down the reason we dream for a very long time, but there's still a lot we don't know.
Psychoanalyst Sigmund Freud theorized that our dreams are symbolic representations of our primitive thoughts, urges and desires. In 2010, researchers hypothesized that our dreams help us remember things. Watch the TED-Ed video above to hear five other science-backed theories about what happens in our heads at night.
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