The quote: "Why then, can one desire too much of a good thing?" comes from which play of William Shakespeare?

The pastoral comedy, "As You Like It", believed to have been written by William Shakespeare in 1599 or 1600 is the play where the quote: "Why then, can one desire too much of a good thing?" is found. These words are said in the play by Rosalind to Orlando (the man she loves) in Act II, Scene VII.

In this instance with the two key characters, a deeper layer of humor is taking place. It is not just a bawdy joke being played by Rosalind on Orlando. A little bit of trademark complicated Shakespearean comedy plotting is going on here. In this scene, Rosalind is disguised as a man. She's trying to "tutor" Orlando in how to woo a woman. The woman in question that Orlando wants to woo is Rosalind. He fell in love with her before her disguise. Now, Rosalind as a man is "pretending" to be "Rosalind" in a role-play to help train Orlando. She makes fake romantic gestures and sounds that Rosalind (Orlando's lady) would make. They are like any stereotype ideas any young man would have about "females" or a person they loved.

So in the joke, it is not about taking something to excess. Rosalind is definitely and truly flirting with Orlando about how much she wants his love. Also, she is making a false joke about (1) how much men are confounded by women and (2) how women like men are also obsessed with the idea of sex.