When do you figure out youre the asshole?

At what point do you figure out that maybe it's you that's the problem? There's this woman that shops at my work that has complained about 14 of the 16 people that work there, all at different times. She's the most maliscious evil woman I've dealt with which is saying a lot when you work in West Hollywood/ Bevery Hills area. Its just funny because we are a really customer oriented store so I can't imagine how going through life must be for her. I should have forcefully hugged her.