You know how you can tell a person who's been using computers regularly since Windows 95 at least, and maintained those cranky boxes of ill-fitting crap?
They have a habit of moving the mouse around the screen while reading something, or waiting for software to install, etc.
It's like a nervous reaction, actually caused by the fact that in Ye Olden Dayes, you could never count on the process to finish correctly. I'm sure it's much more frequent among people living in post-Soviet space - most of the software available to us in the 90s was cracked in Russia and sold for peanuts ("Everything ever made by Adobe on one CD" was a typical example - how much do you think it would have cost in licences?). Of course, the installer often malfunctioned, or the CD was scratched, and you couldn't return it that easily. So you nervously moved the cursor around on the screen, because it's the most expedient way to make sure Windows hasn't frozen. Yet.
You don't really see that sort of thing these days. Then again, you can't buy the latest Professional edition of Photoshop for three bucks, either.