I remember when he first introduced me to Sudoku via a terrible pun involving a certain Count from Star Wars, about 2 years before the US sudoku craze began. I really didn't appreciate the quality of the joke until much later, and now I can't seem to find that quote in the gale logs. I did find a mention of the sudoku t-shirt he made in silk screening at Caltech, circa 1996. So clearly he's been aware of these puzzles for a long time.
My sophomore year I took the Putnam Exam, and was happy to emerge from the test alive, I think I even got a few points of partial credit. Wei-Hwa, as a frosh, did amazingly well. Now that I look it up, I see he was a Putnam Fellow in 1993. Top 5 in the country. Wow.
Seriously, how many people do I know with their own wikipedia entry?