Creative / clever thinking is good. It's where new ideas come from. Practicing creative thinking by reading interesting stories is not a waste of time. Updating based on creative / clever thoughts, on the other hand, is a mistake. The one almost-exception I can think of is "X is impossible!" where a clever plan for doing X, even if not actually implemented, suffices as weak evidence that "X is impossible!" is false. Or rather, it should propagate up your belief hierarchy and make you revisit why you thought X was impossible in the first place. Because the two remaining options are: (1) you were mistaken about the plausibility of X, or (2) this clever new hypothetical is not so clever--it rests on hidden assumptions that turn out to be false. Either way you are stuck testing your own assumptions and/or the hypothesis' assumptions before making that ruling.

The trouble is, most people tend to just assume (1). I don't know if there is a name for this heuristic, but it does lead to bias.