This is probably closer to the fact. She doesn't have conventional thoughts but will suddenly come up with random insightful outlooks on things. She is from a higher dimension, and her brain cannot be trifled with common things. Also, when she puts her mind to it, she can be smart, she DID make it to that high school, which is apparently one of the better ones (see: Yomi talking about how Tomo got in), and she also made it into college.
But, because she is from a higher dimension, she was surrounded by people who wanted to keep tabs on her. Yomi, who was an ESPer, Tomo, who was an ordinary person, Chiyo, who was a time traveller, and Sakaki, who was a robot alien.