Simple. A user asks a question about himself/herself and the user bellow tries to find the correct answer. Try to ask something that you mentioned somewhere on the forums, not the color of your socks.
Person A: What is my favorite Pokémon?
Person B: Pikachu!
Since when have I been wearing contacts?
Person C: Two years.
Who is my idol?
So I'll start. What is my favorite color?