In Act I Scene 4 of Romeo and Juliet Romeo tells his friend Mercutio that he has had a dream and because of it feels that something bad is about to happen. Mercutio, Romeo's loudest and most talkative friend, shrugs off Romeo's premonition and begins a soliloquy about Queen Mab, a very small queen of fairyland who invades a man's mind through his dreams.
O, then I see Queen Mab hath been with you.
She is the fairies’ midwife, and she comes
In shape no bigger than an agate stone(60)
On the forefinger of an alderman.
He continues to describe the mythical Mab as so tiny she fits on a man's finger and is driven around by a small wagon whose wheels are made of spider's legs, cover is made of grasshopper wings, and ropes made from tiny spider's webs. Mercutio explains that the dreams she creates depends on the person she visits.
And in this state she gallops night by night(75)
Through lovers’ brains, and then they dream of love;
O'er courtiers’ knees, that dream on court'sies straight;
O'er lawyers’ fingers, who straight dream on fees;
O'er ladies’ lips, who straight on kisses dream
She has lovers dream of love, lawyers dream of money, and ladies dream of sweet kisses. She also gives parson's dreams of collecting money and soldier's dreams of killing that are so real that he wakes thinking that he hears the drum of battle.
Sometimes she driveth o'er a soldier's neck,
And then dreams he of cutting foreign throats,
Of breaches,ambuscadoes, Spanish blades,
Of healths five fathom deep; and then anon(90)
Drums in his ear, at which he starts and wakes,
And being thus frighted, swears a prayer or two
And sleeps again.
As Romeo brushes off his friend's babbling, Mercutio gets to his point. Dreams are just dreams, and Romeo shouldn't live his life in worry because of them.
True, I talk of dreams;
Which are the children of an idle brain,
Begot of nothing but vain fantasy;