To sum up what someone said earlier: it just is. It works.
The same goes for 1/infinity. It's an idea that can be proven (saying it equals 0, or gets insanely close to 0, as x approaches infinity), but used by itself makes no sense.
It's like comparing the integral of 1/x and 1/(x^2) as x goes from 1 to infinity. By itself, and looking at it, you'd think they're the same, but they aren't.
The first diverges to infinity whle the second converges to 0.
Think about it for too long and you start going crazy and end up believing things that aren't so
