> Is my brain's floating point calculations subject to round off error? > > In the (actual) neurons, is there a representation of real numbers? Where are the numbers in the brain stored?

None of these details are relevant to the bigger picture similarities of non-hardcoded learning from training data. None of these details change the ethics of what's being discussed here.

> I feel like people who assert this neither understand what neural networks are and how brains work.

That's just your bias showing.