Kammala wannan jumla: An haifi Watson a Bristol ga mahaifiyar Welsh da mahaifin Ingila. Yana da 'yan'uwa mata tagwaye masu suna Emma da Lucy da ɗan'uwa, Paul. Ya halarci makarantar Henleaze Junior sannan kuma makarantar Bristol Grammar, makarantar rana mai zaman kanta inda ya lashe kyautar 'Gabbler of the Year', kafin ya tafi Kwalejin Queens, Cambridge, inda ya yi karatun Turanci, ya kammala karatu tare da girmamawa na farko. A jami'a ya kasance memba na Footlights kuma zamani na Stefan Golaszewski, Tim Key da Dan Stevens. Ya kasance wani ɓangare na sake dubawa wanda aka zaba don mafi kyawun sabon shiga a cikin
Perrier Comedy Awards a 2001 Edinburgh Festival Fringe kuma ya kuma yi aiki tare da Key.