Hi ya'll, just had a thought: Cassandra was likely autistic! Yes, I know the character is fictional, but the fact remains that her thought process was not understandable to others. The fact that she was "correct" was overshadowed by the fact that no one believed her. And her 'gifts' were tied up with the fact that she didn't 'properly' return affection to Apollo!
This line of thinking came up because I have been involved in forecasting events and while I wouldn't claim to always be right, I am very familiar with not being taken seriously, even after events have given strong support to my earlier views, especially those most outlandish. This is mostly an example of a savant trait: I arrive at conclusions in unconventional ways, so I am mis-trusted. That my views are unconventional means that others are often not in a good position to judge them AND that there is a high chance of their being notably better than conventional forecasts (as well as being worse than conventional forecasts).