"If a necessary feature has a high astonishment factor, it MAY be necessary to redesign the feature" - emphasis added. But, they're related, as you note. This

"If a necessary feature has a high astonishment factor, it MAY be necessary to redesign the feature" - emphasis added. But, they're related, as you note. This is specifically referencing surprise in the sense of "What, no, that was not what I intended to do!", not in "Ha! That was exactly what I wanted to do; I can't believe it was that easy!" The reality is that latter is very, very rare in UI/UX (more commonly, successful actions don't even register to the user, even if it's slightly novel; it 'just works'). The former...very common, and a thing to avoid.