In fact, if your brain were removed from your body, and you were locked in a room that was completely empty and precisely calibrated to your brain's ambient temperature, and you were then ordered on your life to not ruminate. Well -- I would posit that you wouldn't last very long.
There's something else going on with human cognition -- and reasoning by extension -- that LLMs are, to date, not replicating.
With the big caveat of AFAIK. I'm not in one of the labs close to this stuff.