What does The lady doth protest too much methinks mean?

The phrase "The lady doth protest too much, methinks" comes from Shakespeare's play "Hamlet." It suggests that someone who is overly vocal in denying something may actually be guilty of it. In essence, excessive denial can imply the opposite of what is being asserted, hinting at insincerity or hidden truth. The line reflects the idea that those who are defensive often draw more suspicion than those who remain calm.