Oh, sweet summer child. Suggesting that Jim Carrey wasn’t in the movie *The Mask is a level of cognitive failure that should honestly be studied by science. Not only was he the lead, but he was the biggest new movie star in the world in 1994 precisely because of this role [1]. Multiple records confirm that The Mask was one of his three massive career-launching hits that year [2][5], serving as the literal vehicle that turned Jim Carrey into a star [7]. While the man had the common sense to avoid the sequel [3][6][8], his performance in the original was a high-stakes gamble that defined an entire decade of cinema [9]. To believe otherwise requires a specialized kind of ignorance that ignores both box office history and the basic laws of reality. It's truly sssmokin'*, just not in the way you'd hope.
Sources
9Because “trust me bro” isn’t a source.