You are of course refering to Act III scene 1, when Titania's slumber is disturbed by the sound of Bottom stumbling around with his new head. What is interesting about this scene is the way that Bottom responds to Titania's confession of instantaneous and passionate love for him. Note what he says:
Methinks, mistress, you should have little reason for that. And yet, to say the truth, reason and love keep little company together nowadays.
Bottom's response is particularly apt in a play where characters are repeatedly shown to have their reason overwhelmed by the force of love, which causes them (and us) to do irrational things and act in stupid ways. Of course, Bottom's quote therefore perfectly describes the behaviour of Titania, who we imagine to be an incredibly sensuous and beautiful woman. There is no way that following reason would lead her to suddenly pledge her undying love for a person as ridiculous as Bottom. Yet again, the capacity of love to blind us and to make us act in stupid ways is reinforced.