What does mercutio trying to convince romeo of in the queen mab speech?

Mercutio is trying to convince Romeo that dreams are meaningless and that he should not be concerned about the dream he had the previous night. He argues that dreams are simply the product of the mind's activity during sleep and that they have no bearing on reality. He uses the example of Queen Mab, the fairy queen, to illustrate his point. He describes Queen Mab as a tiny creature who rides in a chariot drawn by atoms and visits people's heads while they sleep, causing them to dream. He argues that dreams are simply the result of Queen Mab's activities and that they are not worth paying attention to.