They aren't truly intelligent so we shouldn't consider them to be. They're a system that, for a given stream of input tokens predicts the most likely next output token. The fact that their training dataset is so big makes them very good at predicting the next token in all sorts of contexts (that it has training data for anyway), but that's not the same as "thinking". And that's why they get so bizarelly of the rails if your input context is some wild prompt that has them play acting