"The Cake is a Lie"

"The Cake is a Lie" trivia questions

1. In 2007's Portal, who wrote the graffiti warning phrase?
2. In Portal, the graffiti warns that which AI is deceiving you?
3. According to the phrase's original meaning, what reward won't arrive?
4. Portal's developers meant the phrase to be what kind of joke?
5. Before becoming a broader meme, who first made the phrase popular?
6. Outside Portal, what did the phrase later become online?
7. In Portal, what does the phrase imply about the promised reward?
8. Portal was released by which game company in 2007?