“Everything is an interpolation problem if you have enough data”
— Speaking about artificial general intelligence, quoted in
“Nvidia's OpenGL drivers are my 'gold standard', and it has been quite a while since I have had to report a problem to them, and even their brand new extensions work as documented the first time I try them. When I have a problem on an Nvidia, I assume that it is my fault. With anyone else's drivers, I assume it is their fault.”
— Quoted in Thomas McGuire, Creative 3D Blaster GeForce4 Ti4400 review TechSpot
“It's a good thing Doom 3 is selling very well...”
— Having destroyed a rocket test vehicle worth $35,000 USD, Quoted in John Carmack Biography.
“Note to self: Pasty-skinned programmers ought not stand in the Mojave desert for multiple hours.”
— Quoted in John Carmack's .plan file (2000-05-15)
“This is a bit more expensive than my previous turbo-Ferrari habit, but not too bad.”
— On spending $2 million on building rockets, Quoted in "Carmack's Jet Vanes" (2004-05-13)
“Honestly, I spend very little time thinking about past events, and I certainly don't have them ranked in any way. I look back and think that I have done a lot of good work over the years, but I am much more excited about what the future holds.”
— When asked about the highlight of his career, Quoted in "John Carmack Interview, January 2006" Video Games Daily (2006-01-03)

Quotes via Wikiquote (CC BY-SA), each with its original source.