Mathematics. Specifically, actuarial mathematics.
One aspect I simply adored in my first job fresh out of school was working at the headquarters of an insurance company. Part of the first day of any of the new hires would be a walking tour of the building (5 floors), and introductions to most of the major staff in the various areas. My office was just outside the president's office, and this would be the typical introduction when they stopped outside my door:
"This is Michael. He's one of our actuaries. We don't know what he does exactly, but he's VERY good with anything computer related."
(mind you, there was an entire IT department on another floor at the other end of the building)