This is a weird opening. Why wouldn't you listen to someone trying to sell you something? The opposite pre-supposes that you have all the information needed to

This is a weird opening. Why wouldn't you listen to someone trying to sell you something? The opposite pre-supposes that you have all the information needed to make a decision about something you may have never encountered before. It may be that you're projecting suspicion onto the salesman rather than acknowledging that your own judgement may not be trustworthy. ;)