If you are even remotely interested in the game industry, and you haven't seen Carmack's yearly QuakeCon keynotes, you should go and do it, right now. In the whole games industry, his keynotes are absolutely unique: He speaks about the industry, his work and other things as he sees fit. Some highlights from his keynotes:
- He explains how he was arguing with Steve Jobs about the iPhone. It's really funny, especially as he tells how he was going like "buuuh" when Jobs announced that you can write web applications for the iPhone. Who else would have the nerve to go to Steve Jobs and argue with him, if not Carmack?
- His random rants on SDKs, developer productivity and stuff. This is a real gold mine, when he goes out and says the Sony PS3 SDK is crap, or how he was reading books about writing better code, and considered none of them useful. The important thing is that he does not simply make things down, but always explains the reasons behind. It's really a difference if someone who has ported games to 20 different consoles personally says that console X has a bad SDK! Plus, the others are extremely careful with their statements, and would never say something negative on one independent vender. Carmack on the other hand does not seem to care too much, knowing that the companies will rather try to fix stuff than to punish him.
- Graphics thoughts. Another cave full of treasures. Carmack speaking about virtual texture mapping and multi-threading is even more interesting now, in retrospective, than it was when I heard it the first time. Now, we know what came out, and the early keynotes give us an idea how the idea started actually.
- War stories: Carmack jumping in and fixing the audio code in Doom3? Going off to a hotel to make a Nintendo DS engine in 4 days? This is practically stuff you would only hear otherwise if you work directly at id.
- Random anecdotes: Carmack grinning when explaining how he is looking forward to start a rocket using his mobile phone is simply hilarious.
- Carmack and academia: From early failures when nobody was interested in Doom, until he was peer reviewing SIGGRAPH papers, it's interesting to see his relationship with the formal research side. Always keep in mind that he said "above all, I'm pragmatic".
You should probably read the excellent book "Masters of Doom", about the beginning of id software, and -- if you are more interested in the technical aspects and a good amount of lore -- Michael Abrash's black book in the extended edition. Personally, I think it's great for the game industry to have someone like Carmack, who is willing to share his experiences with us, and not isolate himself.