You can never have only one!
I wish I could be one of those guys who picked up a GMT-Master from the PX in the 70s and never took it off.
(Mind you, at least part of that isn't because of hobby tendencies or greed, or even how affordable they were then. New watches with their blingy trims and finishes designed to never age will never end up evolving with the wearer even as an only watch.)