In this answer, there is a schematic showing the internals of a 7805 voltage regulator, reproduced below:
First of all, what is the sense pin in the first place? Every 7805 I've ever seen had three pins, Vin, Vout, and ground. Is it internally connected to Vout?
But the main question I want to ask is this: What's with all the shorted-out resistors on that sense line? Is there a reason they're there? Surely something as common as the 7805 doesn't go through individual laser trimming on each die, does it?