Years ago, I started at Google, and was in Charlie's cafe, eating alone. I'm sitting there, and up walks Ken Thompson. He sits down, introduces himself as Ken, and asks me what I work on. We sat there for a good 40 minutes just chatting.
One of my coolest memories of working at Google was that time. He was so down to earth, never bothered to talk up about who he was (even though I knew). I really appreciated that.