All of the time
I whistle all of the time, when I'm not fighting the computer, or reading, especially when i'm working with tools building something. It is like softly, under my breath, like humming. I whistle all kinds of tunes, and mix them. I was wondering if I was the only one that done this, and feel much better now that I find that others do it also. Whistling in it's many forms has been a part of our culture for ever. As to the ones that don't like whistling, they are missing out on a lot of our history. I am old enough that I even remember the great "Whistler" Elmo Tanner. If you are really interested in whistling, and want to hear a master of the art, look up, Elmo Tanner & Whistling on Google.
Chubbo