There's so many keys on my computer that I have no idea what they do, but they sure do stuff when I don't pay close attention to what i'm typing!!

@ArishMell Yes, like a new rectangular window with code kind of letters and numbers!!

@MrAlmostCrazy Oh, the one that shows the formatting for the web-page you are reading? I've had that happen here sometimes.

Yesterday I tried to open an attached document and it came up in Chinese or Japanese! (I found the right way eventually.)