[quote]Literally every human that ever lived and functioned properly was unique. The watch will only work with one specific combination of pieces. There's no one specific combination of pieces for humans. Sure, the general shape is the same, but there are several major differences.[/quote]Per human?[quote]Any such difference in the watch would make it unable to function.[/quote]That's why in this hypothetical scenario there are store brands that vary not only in shape and size but also in price and design.