Answer: Power Initialization

If you take a peek inside the male end of the nearest USB cable, you’ll notice that the outermost pins stick out, like a pair of vampire teeth, beyond the inner pins.

The asymmetric design is hardly accidental. The outermost pins on a standard USB cable carry the power and by extending them beyond the data pins the designers of the USB standard ensured that the power would always turn on to initialize the device before connecting the data.