Daniel Levitin in The Atlantic:
Tom was one of those people we all have in our lives — someone to go out to lunch with in a large group, but not someone I ever spent time with one-on-one. We had some classes together in college and even worked in the same cognitive psychology lab for a while. But I didn't really know him. Even so, when I heard that he had brain cancer that would kill him in four months, it stopped me cold.
I was 19 when I first saw him — in a class taught by a famous neuropsychologist, Karl Pribram. I'd see Tom at the coffee house, the library, and around campus. He seemed perennially enthusiastic, and had an exaggerated way of moving that made him seem unusually focused. I found it uncomfortable to make eye contact with him, not because he seemed threatening, but because his gaze was so intense.
Once Tom and I were sitting next to each other when Pribram told the class about a colleague of his who had just died a few days earlier. Pribram paused to look out over the classroom and told us that his colleague had been one of the greatest neuropsychologists of all time. Pribram then lowered his head and stared at the floor for such a long time I thought he might have discovered something there. Without lifting his head, he told us that his colleague had been a close friend, and had telephoned a month earlier to say he had just been diagnosed with a brain tumor growing in his temporal lobe. The doctors said that he would gradually lose his memory — not his ability to form new memories, but his ability to retrieve old ones … in short, to understand who he was.
More here.