The entertaining bit (similar to the standard floppy-disk "Save" icon), is that most people who have grown up with the web always present... have never seen a radio with true "radio buttons".
I'm kind of ashamed to write this, but I had never realized what "radio button" actually means.
I grew up knowing what they were (I was born in the 80s), but English not being my primary language, I never considered that "radio button" might mean "the kind of button you have in a radio". And I never felt the need to look for a definition :)
To be fair, English is my primary language and I've been doing web development for 10 years and I didn't know why they were called radio buttons until very recently!
I also grew up knowing what they were, and even as a native English speaker, I didn't make the connection to old car radios until I was an adult. I always figured it had something to do with "radius", since they have always (inexplicably, come to think of it) been presented as little circles.
I really think this idea that people haven't seen old technology is somewhat over-sold. I mean, I know about the Beatles, and I wasn't alive in the sixties, I know a good bit about classical antiquity which was thousands of years before my birth, I'm aware of room-sized computers from the '50s, and mechanical computers before that, and yes, I've played with old radios that have radio buttons in my dad's old cars, at thrift stores, and in my dad's 8-track player.
