In college, he figured out how to write a program to compute an arbitrary number of the digits of Pi. I asked him how did he know it was correct? He said "just look at it. The digits are right!"
We were limited in the use of the campus PDP-10 by a CPU time allotment per semester. He was planning to blow his allotment computing pi, he figured he could compute it to 15,000 digits or so. At the end of the term, he fired it up to run overnight.
The PDP-10 crashed sometime in the early morning, and his allotment was used up and had no results! He just laughed and gave up the quest.
Later on, Caltech lifted the limits on PDP-10 usage. Which was a good thing, because Empire consumed a lot of CPU resources :-/