You tell your friend/victim that you had a really interesting dream the night before.
When they ask you to tell it them, you say, "OK, but you'll have to ask me questions requiring the answer 'yes' or 'no'."
What you don't tell them is that you are going to answer 'yes' to every question ending in a vowel and 'no' to every question ending in a consonant.
Was your dream a nightmare? Yes
Was it amusing? No
Did it feature the pope? Yes
Was the pope in the nude? Yes....
And so on.
Effectively the dream is constructed by the questioner. At the end, you point this out to the poor sap. And if the dream has turned out to be really, really embarrassing (which is highly likely) they walk away hating you.