Exactly. Get in line behind me, I'll show you how it's done! I don't get visibly annoyed that other people exist and also need food. I'll be watching and immediately start scanning my items when a self-checkout opens up. I know to scan the produce barcodes, or how to quickly look up the code. I keep my cart close by, but out of everyone's way. If I have to get an age-verification or other cashier intervention, I let them know as soon as they're available. I put my reusable bag in the bagging area, and efficiently load it as I go. I don't stand in anyone's way... I may even leave you cashback from my debit card sticking out of the machine, because I'm a forgetful dumbass!