It depends who the person is. If it's someone that never does that, I'll be pretty surprised, but if it's someone who always does that, I'll probably want to パンチ them in the face.
That they are very stupid and idiotic, but it depends on the person. If it's a person who has a new boyfriend every month, I'll think they are stupid and idiotic. If it's a person who's never 発言しました it before, I'll be shocked and probably think it's true.
if its a person who ALWAYS jumps into things to quickly, probably going a little fast. if its someone else though, like a raitional person, または a shy person, good for them :)