It's news to me too, Midnite. As far as I know, Willie had only been a patient at Windcliff. Maybe Willie prefers to believe that he had been employed there, not unjustly driven to the blink of insanity and equally unfairly confined to a mental institution. It's no more silly than him believing he had a 'romance' with Maggie going on awhile back despite the fact she only considered him a friend and was engaged to Joe at the time.