You click the Start menu, look away, look back, and have no idea what application you were about to run.

While reading a web page, you remember a link that you need to visit as soon as you finish this page, but when you finish reading the current page, you've already forgotten about the other page. (Thanks CJ!)

You still get surprised when streaming video/audio works because you remember the very first RealAudio application.

You set up WinSock to get Windows 3.1 on the net.

You installed a sound card for.... sound.

You remember thinking how nice a 3.5 inch floppy was compared to the old really floppy 5.25 inch version.

You remember "upgrading" to color from monochrome.

You entered programs by hand from magazines. (Anyone remember Family Computing? I'd kill for some of those.)