It claims it will

> Yes, if I don't have the information or knowledge required to answer your question, I will respond by saying "I don't know" or a similar phrase that indicates my lack of knowledge on the subject. However, I will do my best to provide you with the most accurate and helpful response possible based on the information and capabilities available to me.

And sure enough on obvious things it can't know it will say that. "What color is my shirt" for example.

The problem is it will bullshit as confidently as the loudest pub bore, and while it's sometimes right, it's often wrong

When you ask stuff that has a specific answer that's easy to google for, but for whatever reason ChatGPT doesn't have that in its internal model, it'll fall back on telling you when it was last updated and that it may not have the most recent info.