If you have an American English keyboard, pressing Ctrl-[ (control plus left square bracket) is equivalent to pressing Esc. This provides an easy way to exit from insert mode.
So I just learned this after spending the last 3 months full time going nuts over why pressing escape double for me activated some function that I didn't want. Because obviously double escape should not be different from single escape.
So turns out I have the
Ctrl-[ key in use... Which turns out is something poisoned.
Yeah so I'm gonna keep myself civil and not ask why on earth this is a thing, but just kindly ask if there is a way to turn that "feature" off?