In the Alps I was descending fast when I was overtaken by a blonde on straight-barred bike. I could easily see she was blonde because she wore no helmet. She made it look so easy and I guess she was a local. I was on a hire bike but it was a perfectly good descender. When I handed it back they commented that I hadn't put much wear on the brakes.
Of course, when we watch the professionals on the telly, they are descending on cleared roads without up coming traffic (or support vehicles getting in the way).