What made Gabe?

We know Gabe Newell for his various valve-related-shenanigangs... but the guy was 36 and a millionaire already by when he founded the company. So... what did he do before that?
LowSpecGamer video: • Microsoft’s secret war
Special thanks to:
LowSpecGamer for the collab and letting me use his (Maiku made!) drawing assets
MattKC and Wolfgang for dubbing two voice lines
Anya for helping me with the subtitles
lobelia and sofia for helping with some of the editing
I will update soon linking my sources here :3
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