I'm gonna respond to you, because i think you like GPT4 and i do too (even if the only use i trust for now is "Resume me this **lot of text/research article** in less than 200 words", which is already great for a knowledge hoarder like me)

You can think against yourself, a LLM have troubles doing so. Also, they fail spectacularly when asked to do real-life operation: "I have to buy two bagettes at one euros, then five chocolatine, croissants and raisin bread at 1.40, 1.20 and 1.60 respectively, how much should i take with me?" when in my head, i just know it'll be between 20 and 25 in seconds (and in fact it's 23, i took random numbers but they are quite easy to add).