Totally self-contained objects...
I can't even begin to imagine what sort of CPU/network power it is going to take. Certainly things that we have today are not sufficient.
Cease to think in terms of objects driving one another. Start thinnking about them as really independent actors. Very hard to switch.
Word processor, for example...
A letter, a word, a phrase a paragraph. A word knows to show itself in red when it's not in dictionary. But, does the word show itself? Or do letters show themselves? Or do we somehow implement both at once? With a third party to judge between them? How is it going to work? I can't even see it conceptually.
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We have only 2 things to worry about: That
things will never get back to normal, and that they already have.