To be honest, I hadn't really given it a great deal of thought until Jack brought it up, but he's right, whistling is pretty rare these days. As a kid I would hear builders, gardeners, painters, R&B men, milkmen, coalmen (always men!) whistling as they worked - not any more.

I could never whistle very well, and I seem to have completely lost the ability now. And I could never do loud whistles with fingers in my mouth either (I could make a decent enough noise with a blade of grass though).