1. He's curious about obscure holidays.
  2. He's comfortable being alone but enjoys being the subject of mild interrogations.
  3. I have never seen him angry but I have seen him seethe.
  4. He's comfortable being alone even if he's around other people.
  5. He's a master of online/email/facebook comedy but doesn't have a Twitter around to my knowledge.
  6. It's very likely that he has a list about you.