But Muir's invention was meant for himself, while Gillette's razor was clearly not meant for himself. Or was he shaving his neck? So I see these as two differen

But Muir's invention was meant for himself, while Gillette's razor was clearly not meant for himself. Or was he shaving his neck? So I see these as two different kinds of inventors. Randal Peltzer in Gremlins is more like Muir.