Comment by danaris

As akerl_ says, it's not telling you to assume anything. It's talking about behavior, not thoughts.

You can be thinking they're the most ignorant fool on the planet, or you can be thinking that a minute ago you believed them to be so smart, and now that image of them is shattered and you're disappointed...but all this is asking you to do is not to perform that surprise to them, regardless of whether or how much you feel it.