If not expertise at least great enthusiasm
  1. Books, specifically fantasy, specifically fantasy with magic and or dragon like creatures
  2. Psychopaths, the more murdery the less empathy the better. And by better I mean more interesting. I do not think crazy murder people are good
  3. Football but probably not the football you are thinking of. Football that is played with feet and is popular in Europe. I will not pretend I follow most leagues closely but if you want to talk Bundesliga lets do it.
  4. Probably other stuff but maybe not