At first, I thought you referred to those running in for just milk as motherfuckers, not mothers/fathers...LOL I'm not in either category, but am totally guilty of needing one item and walking out with 4-10 more things than I really need! (Paid for of course!)
Anyway...as the manager, not only are you dealing with the customer's demands, but you must deal with the employees and all their "yada,yada,yada, blah, blah, "I'm sick," "I'll be late," "Can I take a break?" Who is actually easier to deal with? The unhappy customer or the unappreciative employee?