The "That's What She Said" meme is a classic, endlessly reusable joke format. It thrives on taking an innocent or serious statement and adding a layer of double entendre. You just need to wait for someone to say something that can be twisted into a sexual innuendo, then immediately reply with the punchline.
It works best in office settings, awkward conversations, or anytime someone accidentally sets themselves up. The humor comes from the timing and the shared understanding of the joke. It's a staple of internet culture, perfect for roasting a friend or lightening a tense moment. Use it wisely, or it loses its charm.