What sort of airport is this that you can be in the air 18 minutes after arriving at the airport? Is this some tiny little airfield somewhere running tiny cesnas or something?

At most major airports it takes 5-10 minutes just to get out of the duty free shop after security! Even in priority lanes I've never got through security at a big airport quicker than 5 minutes - there is always a line of people ahead.

I know some people who have the "special" invite-only etc airline status where someone physically whizzes you through everything in a few minutes and out into a waiting car to take you directly to the gate etc, but that is hardly representative of the sort of person who might benefit from taking HS2