Re: Everybody knows...
“Are you sure” questions are daft. It doesn’t matter whether I’m sure or not, and if it mattered the buttons should be “yes” or “no”. Instead it should say “Press “keep” to keep the booking. Press “remove” to remove the booking” with a “keep” and a “remove” button.
(I’ve done a lot of MacOS development, and there “Cancel” means without exception “Remove the dialog or alert, and continue as if the user had never taken the action causing the dialog to be shown”. Since this conflicts with “cancel” meaning “cancel the booking”, “cancel” cannot be used at all. )