In the category of something that you could do if you are at Denver International Airport and you want to pull somebody’s leg …
There are plenty of signs all over the airport telling which way to go if you want to get to gate B40. You can see some of the signs here. So if you want to pull somebody’s leg, call them on their cell phone and tell them you need to meet with them urgently at gate B40. Or tell them their flight has had a gate change and the new gate is B40 and they had better get over there right away.
Maybe you can guess where I am going with this.
There is no gate B40.
Or maybe there is, and maybe it is like Platform 9¾ at King’s Cross train station in London, the kind of place where most people can’t go. Maybe gate B40 leads to the secret bunkers that lie deep beneath the airport. Maybe gate B40 is connected in some way to the many other conspiracy theories surrounding the airport.
Anyway, yes, armed with the knowledge that there are signs saying how to get to gate B40, and with the knowledge that between gate B38 and gate B42 there is no (visible) gate B40, you ought to be able to pull somebody’s leg with great success.