Saying that "it just uses your name" might be true, but it doesn't tell us how it can use your name. There must be a way that it works.

To clarify, what I believe is that magic works in a top-down way, not a reductionist way. If you were writing a computer program, you would have to specify where the name comes from and what to do in marginal cases. But the Founders believed that each individual came with an XML-tag name attached to them, and the map just tries to figure out that name.

I realize this is an incomplete theory because it doesn't explain what the map does in weird borderline cases (although I can make guesses). I am using this theory (which we can derive by comparing the map to Harry's pouch, and to broomsticks, and to Transfiguration) to reject hypotheses that involve a reductionist, computer-program approach to magic.