When you work in retail, people are always fucking your shit up. You will pick up some amazing folding skills, only to see your perfect stacks get reduced to a huge pile of shirts by some asshole looking for size "doesn't exist." This doesn't change when you get older. Sometimes a co-worker will forget to carry a zero on a spreadsheet, sometimes your boss will skip town with the secretary and leave you to meet with a huge client and warn you not to fuck it up. Just keep your cool. These things happen sometimes, and what you'll come out of it with is grace under pressure.