[1][2] David attended Wheaton College in Chicago initially following a path in Chemistry and then Physics, but with two years to go until completion changed once more to Psychology, earning a degree.
After which he found a job as a junior programmer at Bunker Ramo Corporation, a company that built supermarket computer systems.
[5] The idea for Tempest was of monsters appearing from a hole in the ground, a scenario from a movie which Theurer had seen as a child.
He left in 1990 to work full-time on DeBabelizer, an automated image editor, graphics optimizer, and file converter for Windows and Macintosh.
[7] On the way to fireworks displays at Moffett Field on July 4, 1983, Theurer used his Porsche 928 to chase down a hit-and-run driver who had struck Michael McCully, a 15-year-old boy from Los Altos.