This is my favorite Notepad memory: in the late '90s I went through a six-month stretch where Internet Explorer's "View Source" command just totally stopped working. It would normally open up the HTML source of a page in Notepad and suddenly not having this made debugging ... challenging to say the least. Nobody else that I worked with had this problem and nobody could figure out what had happened to me.

The culprit turned out to be an inexplicable IE bug where View Source wouldn't work if you had a shortcut named "Notepad" on your desktop. It didn't even have to be a shortcut to Notepad, it just had to be named that. The fix was to just rename the shortcut "NotepadX" and then View Source worked again.