I went to close a text window that I wasn’t looking, but it wouldn’t close. I kept hitting the same key command (⌘-w) over and over. (the MacOS command to close a window).
I finally looked at the text window and saw a bunch of this: ∑∑∑∑∑∑∑∑ (option-w)
Also, the ⌘ character is really rad-looking.