Critical Grocery Error

Today I decided to go grocery shopping and drive my car to the store for the distinct purpose of buying more groceries and having a car in which to carry them. The store was in the next town. I had driven through the town, but had not stopped there. The first clue that I was in unfamiliar territory was when I turned into the exit. Driving on the left hand side of road means the entrance is on the LEFT! I almost ran into one lady. Then I walked in the door after picking up a cart in the parking lot (free cart this time, so I was grabbing one) and all I see is an elevator and a flight of stairs. I ask another lady walking in if I take was to the cart onto the elevator, "yes..." she replied as she flew down the stairs. Fortunately there were only 2 floors and I came out in the middle of the store - free carts were already there, so I looked like a newby (again) coming down with an empty cart instead of going up with a full cart. I proceeded to shop to my hearts content. Bought snacks and dinner while keeping in mind that all the fresh and prepared food is only good today and tomorrow. (It definitely affects what quantity you buy). I bought a few large bottles of water, couple of Sprites, 8 pk of small waters, etc. Lots of heavy items to transport in my car. Happy as I could be that I wouldnt be carting them through the mall and down the block to walk home from the local grocery. Even picked up my favorite American magazine. I check out with my unpopular American ATM card which requires swiping and signing (they only want you to have a CHIP and PIN card, I apologized again for having the bad kind of card. In fact some places will not accept a swipe and sign card, which is such a bummer when I'm trying to buy something and actually find what I want.)
I check in with the parking lot attendant because there are signs posted everywhere that you must show your Waitrose receipt to leave the parking lot. I cant find the exit, so he directs me and could care less about seeing my receipt. I navigate my way out of town and drive back home without any wrong turns, only to realize that in all my happiness of using the car for this trip that I now have to park in the car park (garage) and carry my HEAVY 7 bags up 2 flights of stairs, down the block, around the corner, find key for exterior door, up 4 more flights of stairs, find other key for apt. door and then reverse and do it all again for the next load. happiness bubble burst!

Lesson learned: drink tap water!