Movies can influence fashion and language. I have to remember to cycle my TV shows, so that frequently used language doesn't stick with me. Because of TV my mother didn't have the Louisiana accent her grandmothers had. I appreciate how just one movie can change my mood. When I'm angry or depressed I like to watch movies that begin with turmoil but end happily ever after to show that problems can be fixed. And that makes me feel better.
Movies can take you away from this world no matter how dreary or stressful it may be. You can fall in love with the characters and they can make your day just like a good friend might. (Ok that last bit might just be for introverts like me :)