I would like to please the reader, and I think that surprise has to be an element of this, and that may necessitate a certain amount of teasing. To shock the reader is something else again. That has to be handled with great care if you're not going to alienate and hurt him, and I'm firmly against that, just as I disapprove of people who dress with that in mind - dye their hair blue and stick safety pins through their noses and so on.