The late Sjef Poort performed the voice of Forgetful Jones on Sesamstraat, the Dutch co-production of Sesame Street.
Sjef was mostly active during the 80's, and performed voices until the mid-nineties. For a long time, he was one of the main singers. He also performed the voices of Hard Head Henry Harris, and Oscar in the song "Swamp Mushy Muddy" (one of the only Oscar appearances of that era.)
Despite Forgetful Jones being one of the least popular characters on Sesamstraat, he is heavily used as a main character.