How can you be sure without taking an internet quiz?
People can have any one of these four personalities. Which personality is yours?
Do you understand the purpose of your friend's books?
If you can tell them apart, you're halfway there.
Prepare for what may (or, conceivably, may not) be the hardest quiz you will ever take.
It’s not as simple as it looks! (But it’s not that much harder, either.)