Take a look at Stephen Wolframs recent article: https://writings.stephenwolfram.com/2023/02/what-is-chatgpt-doing-and-why-does-it-work/

It's a long, technical read .. but well worth the effort.

It's clear that ChatGPT is something more than just a calculator or look-up table of word probabilities.

Maybe not sentience, but certainly something brain-like is going on.