In retail, the number of customers who are convinced they know better than you is endless… Better than you when it comes to the products, better than you in terms of your store's policies, and better than you when it comes to the legalities under which you're trading. Having access to all the information with little understanding has emboldened people into thinking that they're experts after a few Google searches, even on impressively technical subjects. Of course, the rehearsed script often ru…