> Prompts and LLMs most certainly do not work like that.

It quite literally works like that. The computer is now OS + user-land + LLM runner + ML architecture + weights + system prompt + user prompt.

Taken together, and since you're adding in probabilities (by using ML/LLMs), you're quite literally getting "the computer only does exactly what you tell it to do!", it's just that we have added "but make slight variations to what tokens you select next" (temperature>0.0) sometimes, but it's still the same thing.

Just like when you tell the computer to create encrypted content by using some seed. You're getting exactly what you asked for.