Same can be said about auto dealerships. If you are a car buff, or shopping for a specific model and did your homework, chances are you will know more than they do.
Thanks to the Internet, the customer is more informed then ever before. Technically the salesmen have access to the same info, but probably don't care...except the sales people who are passionate about what they sell.
The reality about most "Jewelry" stores that sell watches is that watches are often the afterthought for the man whilst shopping for female jewelry. Watches are treated the same as a bracelet or neckless- what looks good, what's your style -vs- a technical instrument of timekeeping.