Thanks for your comment Ali! This is actually a heated discussion on https://medium.com/geekculture/prompts-to-boost-chatgpt-answers-engineering-data-science-chatgpt3-chatgpt4-607fc9fde7d1 .

I am looking into this in more detail! I think it is because ChatGPT gets some updates in the service from time to time and possibly also in the model - either with some batches of new data or with the information from the user's conversations.

Nevertheless, if you ask ChatGPT when is your latest update, you get the following response:

" I don't have information about events or updates that have occurred after September 2021 unless they have been widely covered in publicly available sources."

So this unless statement might provide us a hint!