After the quote from the Olympiad News 2003, here the continuation taken from the Olympiad News 2004:

And then there was one

MSO archivists like to keep a close eye out for perennial MSO medal winners. At least five people won a medal in each of MSO 1 to MSO 5: Pentamind specialists Demis Hassabis and Dario De Toffoli, mental calculator Rober Fountain, speed reader Anne Jones and backgammon star John Clark.

Demis was too busy running his software company to attend MSO 6; Anne Jones had her event there cancelled when she was the only entrant. John Clark wasn't at MSO 7 here in Manchester and we hear that unfortunately Robert Fountain has had to reluctantly cancel his scheduled appearance at MSO 8 due to ill health. (The entire MSO team wishes you all the best for a swift recovery, Robert). This means that we believe there's only one person who has won a medal at every event from MSO 1 to MSO 8: Dario De Toffoli. We salute you, Dario!