But that's just the analog model of a digital world. From the computer's perspective, it doesn't know 2.2V from 2.27 -- all it knows is "1".
It's the classic image of converting an analog signal to a digital one that I'm thinking of, the one where it assigns a number to a value at a certain point in time. You're not sympathizing with the computer, I don't think.
I mean, in digital transmission, ones and zeros are usually represented by transitions between two values, not even a constant state value. It's not how it's represented that is important, it's the fact that they are discretely-stepped, discretely-timed values that's important. It's entirely an abstract concept.
I mean, even when you digitize (and back), one always has to take into account the limitations of whatever digitization process (or back) was used, to accurately re-render the analog signal.