The cashiers are definitely the most awkward out of the other stores in the area. One time I went in there to get some crafty beer. When I approached the register to check out the cashier asked how I was doing. Before I could give my reply the cashier said "oh good". Then she realized what she had done and I tried not to laugh. You could've cut the awkwardness with a knife.
That's one cool cashier. You misunderstood. She asked how you were doing... saw the beer, and said "oh good!" because the beer.