Cary Lu was a mentor to me, even though he always treated me as a peer. He was generous with his time and knowledge, and never pretended to know more than he did. Of course, because he knew virtually everything, he didn't have to.
I remember during his research for The Race for Bandwidth, he would call me from time to time with questions about the fundamentals of Internet bandwidth that caused me each time to plumb the depths of my knowledge. I always came out of those conversations with better questions (if not a better understanding) of the subject.
When I was doing my own research for Real World Scanning and Halftones in the months after Cary passed away, I would constantly find articles he'd written in Macworld and elsewhere over the last few years to help guide me. His voice was always there in the background, and I and my two co-authors dedicated the book to him.
It's hard to think of him as gone, because he is so present in so many important ways. I sometimes expect to still get a call from him, asking for one last detail.
One day the 'Q' key broke on a Mac Extended keyboard at Point of Presence. I messed around with it for a while, and then gave up. I threw it in the trash, even. But then either I called or saw Cary shortly after this. He was appalled! He said something along the lines of, how often do you need a Q? To "quit" a program, I said. Well, you can use the menu. Anyway, you can always paste a Q from KeyCaps into the Scrapbook and use it as you need it.
Cary won out, I fished it out of the trash, and a recent visit (3 years after this) to my former business found that keyboard sitting there in use...and a Q in the Scrapbook.