People used to wear gold as jewelry thousands of years ago. And some people still do just that. That behavior predates a great many currencies. For example I'm pretty confident people shall still wear gold as jewelry long after the EUR currency shall be dead.
Enter any jewelry store in the west now and they'll tell you: men buy jewelry too now. But it didn't use to be that way: typically a watch was the only jewelry a man was allowed to wear.
I've got a very nice japanese mechanical watch which shows day of the week, day of the month and power reserve in addition of the time. Got it for 300 EUR brand new at a "family sale".
When I'm wearing that watch there's some device responsible for the zombification of the west I can do without: my smartphone. Adjusting it manually once in a while doesn't seem that bad of a deal.
Historically speaking, this was only true in recent times (the last few hundred years). Visit a history museum and you'll find all sorts of jewellery and ornaments worn by men over time.