If you wanted an exact simulation, the n-th digit is important. But if you just want some system where some other (possibly intelligent) behaviour emerges, the n-th digit is not important.
Well, it would by all means be awesome if we could build an intelligent system that didn't match the one we already have.
And we even have an existence proof that such a thing is possible, given enough design time. Unfortunately, the existence proof says nothing about the odds of doing so very quickly -- in less than, say, a million years, which is very quick by historical standards.
