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. He has said that earning the degree had helped him create addictive games by using the same techniques originally used on pigeons.
David worked for the college data processing center for approximately six months after graduating. After which he found a job as a junior programmer at Bunker Ramo, a company that built supermarket computer systems. He moved to California and joined National Semiconductor in 1976. Six months after joining National Semiconductor a co-worker was hired as Manager of Programmers for Atari Games and subsequently hired David without an interview.
Despite not liking the sport, David's first game for Atari was Four Player Soccer. During the development of Missile Command, David regularly had nightmares which involved the bombing of nearby towns. The idea for Tempest was of monsters appearing from a hole in the ground.
Theurer cites Pong as his inspiration to become a game designer.
He left Atari in 1990 to work full time on DeBabelizer, an automated image editor, graphics optimizer, and file converter for Windows and Macintosh.
On the way to fireworks displays at Moffet Field on July 4th, 1983, David used his Porsche 928 to chase down a hit-and-run driver which had knocked down Michael McCully, 15 of Los Altos. Michael suffered a severed spine and was paralised from the waist down. The driver returned to the scene where the California Highway Patrol arrested him for hit-and run, drunken driving, giving false information to a police officer and driving without a license. David was touted as being a hero and was praised for his efforts by the California Highway Patrol.
Theurer was born and raised in Fergus Falls, Minnesota, where some of his family still reside.