Feigned surprise is a different concept. Feigned surprise is when you act surprised that someone else doesn't know something; it's when surprise is used to illustrate that someone has failed to meet your expectations. "you've never programmed Haskell?!?!" would be feigning surprise. For one thing, it's not surprising that someone would have not programmed Haskell; lots of people have not programmed Haskell. For another thing, it doesn't add anything; it's tantamount to saying "I'm disappointed you haven't programmed Haskell". The idea is that if someone hasn't seen or experienced something, you shouldn't act surprised; you should act excited to introduce something new to the person.