I like how everyone has a different opinion about how a smart person has to be, but in most cases people are referring to certain traits that do not correlate with intelligence (and frequently could indicate deviation in either direction), and that's plausible since intelligence is such an abstract notion.
For instance, recognising patterns, and acting on those patterns are two different things. One might notice that acting on the patterns can bring him success/economical safety and what he considers joy or effortlessly having goods. But the other one can make a step further and consider that in the steady state he will not be any happier. If both happen to make this logical step, they might have to make a decision based on their preferences, which is highly subjective.
For me, intelligence is not comparable. To be more honest, I think there is only a partial order, and for that, I'm not sure.