It is better at doing "translations" from one "language" to another "language". While it does know stuff and can answer questions about what it knows, that isn't its strength.

If you can do "here is the structured data, summarize it and make sure to present this information" it can do that quite well.

So far I've played with GPT doing a zero shot classification of HN titles and CSV hourly weather data to summary. In each case, it has done quite well.

Neither of those are things about what it "knows."