Opinion-Changing Dream

A character is bored or disinterested about learning something. Or he is just completely uninterested in a certain topic and doesn't understand why other people value it so much? Usually it has something to do with history. Or he is just a mean person who doesn't understand why his behaviour is wrong. He is comfortable with his ignorance and just goes off doing banal or evil things. Sometimes he even pokes fun at other characters' seriousness about the topic.

Then he or she goes to sleep and has a dream. Usually some legendary character arrives and provides the person with a lot of background information about the topic. Sometimes the dreaming ignoramus is put in the action himself. Now he gains knowledge and enthusiasm about a topic he actually knew nothing about. Or he finally starts to see things from his victims' point of view.

When the character eventually awakes he makes a Heel Face Turn. He finally realizes the importance of learning math, respect for your country, respect for your ancestors, respect for people he formerly threatened or hurt,... and so on. In most cases he even becomes an vocal supporter of the cause.

This corny plot device was very popular in old educational films and tv series.

When a character actually wishes things to be different, only to find out that life has changed for the worse, you have a Be Careful What You Wish For. In both cases the character always wakes up, glad that things are just the way they are.

Film

 * Wayne's plan for Waynestock in Waynes World 2 is the direct result of a dream with Jim Morrison telling him to set up a huge show in Aurora. Others he recruits also mention having the Jim Morrison dream later on.

Literature

 * A Christmas Carol: Ebenezer Scrooge hates Christmas and helping the needy. But after a long dream where he is visited by his late partner Jacob Marley's ghosts and then three more ghosts he changes his character completely and becomes a good person.
 * One Berenstain Bears book centered on environmentalism had Papa Bear go through one after he decided he didn't need to recycle or plant trees to replace the ones he cut down.

Live Action TV

 * An episode of Sister Sister ("I Had A Dream" (1998)) features one of the sisters ridiculing the deeds of her African-American ancestors and is reluctant to carry on with her own miserable life. In her dream she is visited by several historical Afro-American characters who all claim they want to give up and do something else. She convinces them to do otherwise and do the historical deed that they are famous for. When she wakes up she respects her ancestors.
 * In an episode of Cosby, Bill Cosby's character Hilton Lucas is disinterested in studying William Shakespeare, until he has a dream where Shakespeare himself(played by Tom Conti) explains the relevance of his works. One notable Casting Gag moment finds Lucas cast in the role of King Lear, with Sabrina La Beauf(Sandra from The Cosby Show) as Gonreil. By the end of the episode he's much more interested in Shakespeare's plays.

Western Animation

 * In the Pluto cartoon, "Pluto's Judgment Day", Mickey Mouse punishes Pluto for chasing a little kitten. Pluto then goes to sleep and has a nightmare where he is sent to Hell and tortured by several cats. When he awakes he changes his ways and acts gentle towards his feline friends.
 * The Porky Pig cartoon Old Glory has Porky struggling to get through the Pledge of Allegiance. He falls asleep and is visited by Uncle Sam who tells him about the American War of Independence. Porky learns the value of American freedom and wakes up. Now he is able to recite the entire Pledge from memory.
 * Subverted in the Looney Tunes short "Pigs Is Pigs", where Piggy is seen eating too much for his own good. When he goes to bed he has a nightmare where a scientist forcefeeds him. Eventually Porky has a Balloon Belly and eats one more piece of food before he explodes. After he wakes up, he still rushes downstairs to continue eating, having learned nothing!
 * Another Looney Tunes example, "The Big Snooze" has Elmer Fudd tearing up his Warner Brothers contract after being bested by Bugs Bunny one time too many. Bugs invades his dreams and induces a truly bizarre nightmare as only Bob Clampett can produce, prompting Elmer to get back to work.
 * The Tom and Jerry cartoon "Heavenly Puss" shows Tom dying and going to Heaven. There he is told that he should go to Hell, but if he can make Jerry sign a contract of forgiveness he may enter Heaven. Tom goes through great lengths to do so, but in the end he fails and is cooked in Hell. Then it turns out it was All Just a Dream and he hugs Jerry to become friends again.
 * Mocked in South Park's "I'm A Little Bit Country" episode where Cartman acts as if he doesn't care about American history so that he can get into a coma and have an opinion changing dream.
 * He also elaborately stages incidents that would render him unconscious so that he can have the educational dream and thereby avoid the bother of actually studying. After many amusing failed attempts, he succeeds.