One was at Microsoft. He kept his office dark except for a large illumiated picture of Jesus on his wall. Everyone spoke reverentially of him and knew to leave him alone. Another was at a small company I worked at. He was my senior. He disappeared for 10 days and returned with about 10,000 lines of 68000 asm code that utilized all 16 32bit registers to pass parameters instead of the stack. I was tasked with testing it. I never found anything wrong with it that weren't minor nits.